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At least 19 recordsLinked to original sources

PubMed1983

Evidence for the existence of a neurotensin-containing pathway from the endopiriform nucleus and the adjacent prepiriform cortex to the anterior olfactory nucleus and nucleus of diagonal band (Broca) of the rat.

The origin of neurotensin-like immunoreactive fibers to the anterior olfactory nucleus and nucleus of the diagonal band of Broca of the rat were elucidated experimentally using the indirect immunofluorescence method. Neurotensin-like immunoreactive fibers located in these areas decreased remarkably in numbers on the operated side after the destruction of the ventral part of the endopiriform nucleus and the adjacent prepiriform cortex where numerous cells with neurotensin-like immunoreactivity were detected. This strongly suggests that such cells located in the endopiriform nucleus and the adjacent prepiriform cortex send a neurotensin-like projection ipsilaterally to the anterior olfactory nucleus and to the nucleus of the diagonal band of Broca.

Animals↗

PubMed1997

GABAA receptor modulation by protein tyrosine kinase in the rat diagonal band of Broca.

The diagonal band of Broca (DBB) is involved in a wide array of physiological functions which are, in part, mediated by activation of GABAA receptors. DBB is enriched in GABA and protein tyrosine kinase (PTK) immunoreactivity. Whole-cell patch-clamp recording were performed from acutely dissociated DBB neurons to investigate the involvement of PTK in GABAA receptor function. The activation of GABAA receptor by the selective agonist, muscimol (5 microM) was dependent on the presence of intracellular ATP. Omission of ATP in the intracellular medium resulted in a fast decrement of the response whereas inclusion of sodium orthovanadate (100 microM), a non-specific phosphatase inhibitor, augmented the response and inhibited 'run down' of the response. Genistein (100 microM) and tyrphostin B-44 (-), specific inhibitors of PTK, attenuated the response to muscimol. The muscimol response was not affected by daidzein (100 microM); an inactive analogue of genistein) nor by tetraethylammonium bromide (1 mM). These observations suggest that phosphorylation is important for the activation and long term maintenance of GABAA receptor function. PTK phosphorylation, which has been previously identified as an important event in signal transduction, may modulate GABA mediated neurotransmission in the forebrain.

Adenosine Triphosphate↗

PubMed2003

Pressor effects of L-glutamate injected into the diagonal band of Broca of unanesthetized rats.

The diagonal band of Broca (dbB) is involved in central cardiovascular control. In the present study we compared the effects of microinjections of L-glutamate into the dbB of unanesthetized rats with those observed after the injection of L-glutamate into the same area in urethane-anesthetized rats. The microinjection of L-glutamate (10, 30, 100 or 200 nmol/200 nl) into the dbB of urethane-anesthetized rats caused dose-related short-lasting depressor responses The depressor responses to L-glutamate were accompanied by dose-related heart rate reduction. The cardiovascular response to the injection of L-glutamate (10, 30 or 100 nmol/200 nl) into the dbB of unanesthetized rats was characterized as a long-lasting pressor response without consistent heart rate changes. The pressor response was dose-related and presented an ED(50) of approximately 30 nmol/200 nl. The fact that the chemical stimulation of the dbB with L-glutamate caused only dose-related pressor responses in unanesthetized rats suggests that under normal conditions the dbB is predominantly a pressor area. After the characterization of the pressor response to L-glutamate microinjected into the dbB of unanesthetized rats we studied the mechanisms involved in the mediation of these responses. The pressor response to L-glutamate (30 nmol/200 nl) into the dbB was blocked by intravenous pretreatment with the vasopressin antagonist dTyr(CH(2))(5)(Me)AVP (50 microg/kg), suggesting the involvement of circulating vasopressin in this response. Further evidence of the involvement of the endocrine vasopressin system in the pressor response to L-glutamate injected into the dbB was provided by hypophysectomy since L-glutamate (30 nmol/200 nl) microinjection into the dbB of hypophysectomized rats caused only depressor responses. We presently report that chemical stimulation of the dbB with L-glutamate caused only pressor responses in unanesthetized rats that were mediated by vasopressin release into the systemic circulation. Additionally, the results confirmed the existence of an L-glutamate-sensitive depressor system in the dbB, which is predominant in urethane-anesthetized rats or may be evidenced in unanesthetized hypophysectomized rats.

Animals↗

PubMed1979

Interspecies aggression in the rat: the role of the diagonal band of Broca.

Electrolytic lesions of the diagonal band of Broca were made in rats which had previously not killed mice (DBPt) and in rats which had no experience with mice prior to the beginning of the experiment (DBN). The lesions induced killing in 12 of the 20 naive (DBN) rats, but in only 1 of the 16 pretested (DBPt) rats. The region of the diagonal band is projected upon or has extensive projections to many regions of the central nervous system in which lesions have previously been found to induce muricide. The behavior induced by diagonal band lesions and lesions of these other regions was compared.

Aggression↗

PubMed1998

The supramammillary nucleus innervates cholinergic and GABAergic neurons in the medial septum-diagonal band of Broca complex.

In the present study, the connectivity between two subcortical nuclei involved in hippocampal theta activity, the supramammillary nucleus and the medial septum-diagonal band of Broca complex, was examined. Targets of the supramammillary afferents in the medial septum-diagonal band of Broca complex were identified by combining anterograde transport of Phaseolus vulgaris leucoagglutinin with immunostaining for putative postsynaptic neurons, i.e. for parvalbumin and choline acetyltransferase that are known to label the GABAergic and cholinergic neurons, respectively, of the medial septum-diagonal band of Broca complex. Double retrograde transport experiments using the tracers horseradish peroxidase and wheat germ agglutinin-conjugated colloidal gold were employed to identify supramammillary neurons that project both to the hippocampus and the medial septum-diagonal band of Broca complex. Phaseolus vulgaris leucoagglutinin injections into the supramammillary nucleus of the rat resulted in dense fibre and terminal labelling in the medial septum-diagonal band of Broca complex. Labelled terminals formed asymmetric synapses mainly on distal dendrites of medial septal neurons. Proximal dendrites and somata were rarely contacted. The supramammillary afferents showed no target selectivity for a particular cell type; they innervated both cholinergic and GABAergic cells. Occasionally, perisomatic, basket-like terminals of supramammillary origin were found around parvalbumin-containing neurons. Double-retrograde experiments revealed that at least 25% of the supramammillo-hippocampal cells also projected to the medial septum-diagonal band of Broca. These data suggest that the nucleus, known to modulate the hippocampal electrical activity directly by the supramammillo-hippocampal pathway, also has the potential for an indirect action via the innervation of both the GABAergic and cholinergic septohippocampal neurons. This dual modulation may originate, at least in part, from the same population of supramammillary neurons.

Animals↗

PubMed1997

Vasopressin receptor subtypes differentially modulate calcium-activated potassium currents in the horizontal limb of the diagonal band of Broca.

The actions of vasopressin on acutely dissociated neurons within the rat horizontal limb of the diagonal band of Broca were examined using the whole-cell patch-clamp technique. Vasopressin elicited two distinct responses in 45 of 62 neurons. In one group of cells, 300 nM vasopressin decreased voltage-activated outward currents (26/45 cells) whereas in a second group, vasopressin increased outward currents (19/45 cells). The vasopressin-mediated decrease in outward currents was blocked by 1 microM Manning compound, a V1 receptor antagonist, suggesting that this response was mediated via V1 receptors. In contrast, the vasopressin-induced increase in outward current was blocked by 1 microM d(CH2)5)1,D-Ile2,Ile4,Arg8,Ala9, a V2 receptor antagonist, indicating that V2 receptor activation underlies this second response. When cells were perfused with 0 Ca2+/50 microM Cd2+, application of vasopressin did not cause any change in voltage-activated outward currents, suggesting that vasopressin modulates a calcium-dependent conductance. In the presence of 25 nM charybdotoxin, an Ic channel antagonist, vasopressin application did not influence outward currents, indicating that vasopressin modulates Ic. Currents through voltage-gated calcium channels which are responsible for activation of Ic were unaffected by vasopressin, suggesting a direct effect of vasopressin on Ic channels. These observations indicate a differential modulation of Ic channels by vasopressin via V1 and V2 receptors in the horizontal limb of the diagonal band of Broca. Our data also demonstrate the ionic mechanisms whereby vasopressin may act at V1 for V2 receptors to influence the excitability of the horizontal limb of the diagonal band of Broca neurons.

Animals↗

PubMed2003

Lesions of the diagonal band of broca enhance drinking in the rat.

This study examined the role of the diagonal band of Broca (DBB) in drinking behaviour and vasopressin release. Adult male rats were anaesthetized (pentobarbital 50 mg/kg) and received DBB injections of either ibotenic acid (0.5 microl of 5 micro g/ microl) or vehicle (0.5 microl of phosphate-buffered saline). Although baseline drinking and urine output were not affected, drinking to 30% polyethylene glycol (MW 8000; 1 ml/100 g s.c.) and angiotensin II (0, 1.5 and 3.0 mg/kg s.c.) were significantly increased in ibotenic acid in phosphate-buffered saline (DBBX) rats. Drinking to hypertonic saline (0.9, 4 and 6%; 1 ml/100 g), and water deprivation were not significantly affected. DBBX rats had significantly lower basal heart rates than controls but the cardiovascular responses to infusions of angiotensin II (100 ng/kg/min i.v. for 45 min) were not affected. DBBX rats had significantly higher basal vasopressin, but angiotensin-stimulated vasopressin release was not significantly different. Although the DBB is not involved in basal water intake, it is involved in dipsogenic responses to hypovolemic stimuli and possibly basal autonomic function and basal vasopressin release.

Angiotensin II↗

PubMed1995

In vivo intracellular recordings of medial septal and diagonal band of Broca neurons: relationships with theta rhythm.

Transmembrane potentials from medial septal and diagonal band of Broca (MS-DBB) neurons and hippocampal field activity were recorded in curarized and urethanized rats. MS-DBB cells were studied during large amplitude irregular activity and during hippocampal theta rhythm, elicited by either sensory (i.e. stroking the fur on the animal's back) or electrical stimulation of the reticularis pontis oralis nucleus (RPO). Three types of cells were described according to their firing pattern and the characteristics of their "intracellular theta" rhythm. Type A neurons displayed continuous rhythmic oscillations in the membrane potential (Vm) of approximately 17 mV. These oscillations generated rhythmic high-frequency spike trains which were phase-locked with hippocampal theta rhythm. Type A cells revealed intracellular theta rhythm even in the absence of hippocampal theta rhythm, suggesting that the activity of this type of cell was the most important in hippocampal theta genesis. Type B cells were characterized by marked postspike after hyperpolarization and intracellular theta oscillations of smaller amplitude than in type A cells. Type C cells revealed a postspike afterdepolarization and a lower amplitude, intracellular theta rhythm only in the presence of hippocampal theta rhythm. Type C neurons could fire slow spikes at depolarizing (46% of cells) or hyperpolarizing (15% of cells) Vms. Type B and C cells were intracellularly stained with Lucifer yellow. Although type B and C neurons revealed dissimilar electrophysiological properties, they had comparable morphological shapes. RPO electrical stimulation generated hippocampal theta rhythm and intracellular theta rhythm in types A and B cells but not in type C cells, and increased the spike rate in type C neurons. Electrical stimulation of the fornix only evoked synaptic responses in type B and C neurons, with antidromic responses being elicited in 12% of type C cells. These results indicate that probably most of the type A rhythmic cells did not receive direct hippocampal feedback and that at least some type C cells were projecting neurons. The present findings demonstrate that theta rhythm oscillations in the Vm of MS-DBB neurons elicit different rhythmic discharge patterns.

Animals↗

PubMed1999

GABAA receptor modulation of temperature sensitive neurons in the diagonal band of Broca in vitro.

Several regions of the brain, including the horizontal limb of the diagonal band of Broca (HDB), contain neurons that are responsive to changes in local temperature. These neurons are hypothesized to participate in thermoregulation and sleep-wake control. The HDB contains a large number of gamma-aminobutyric acid (GABA) terminals, and it has many neurons that utilize GABA as a neurotransmitter. Therefore, in this study we characterized the in vitro effects of the GABAA receptor agonist muscimol (0.5, 0.25, 0.1 and 0.0625 microM doses) and the GABAA receptor antagonist bicuculline (3.0 and 1.0 microM doses) on the firing rate and thermosensitivity of HDB neurons. Of the 51 neurons recorded in a submerged slice chamber, 53% were warm sensitive, 45% were temperature insensitive and 2% were cold sensitive. All neurons exposed to bath applied muscimol exhibited reductions in both firing rate and thermosensitivity. Muscimol induced reductions were maintained for at least 20 min after washout. Neurons exposed to bicuculline had no change in firing rate or thermosensitivity. However, after bicuculline washout there were reductions in both firing rate and thermosensitivity. These findings support the hypothesis that GABAA receptor induced inhibition of HDB thermosensitive neurons can modulate both thermoregulation and sleep-wake control.

Animals↗

PubMed1999

Different effects on learning ability after injection of the cholinergic immunotoxin ME20.4IgG-saporin into the diagonal band of Broca, basal nucleus of Meynert, or both in monkeys.

Immunotoxic lesions of the diagonal band of Broca (VDB) in monkeys disrupted cholinergic input to the hippocampus, producing impaired learning of visuospatial conditional discriminations but not simple visual discriminations. Immunotoxic lesions of the basal nucleus of Meynert (NBM) deprived the cortex of most of its cholinergic input, producing impaired learning of simple visual discriminations but not visuospatial conditional discriminations. Combined lesions of the NBM + VDB resulted in impaired learning of both types of task. The impairment after NBM lesions ameliorated with time but could be reinstated by a low dose of the glutamate blocking drug MK801, which, at this dose, did not impair simple visual discrimination learning in normal monkeys. The cholinergic projections from the NBM and VDB may sustain the function of the glutamatergic pyramidal cell pathways within the cortex and hippocampus, respectively.

Analysis of Variance↗

PubMed1979

Responses in the diagonal band of Broca evoked by stimulation of the fornix in the cat.

1. Field potentials were recorded within the boundaries of the septal component of the diagonal band of Broca following stimulation of the fornix. The position of the recording electrode was marked by pressure injection of Alcian blue dye. 2. Stimulation of the medial aspect of the ipsilateral fornix produced a simple field caudally consisting of a short duration, short latency negative wave (N1) and a later small prolonged positive wave (P1). It is suggested that N1 is due to antidromic activation of the cells and P1 to their recurrent inhibition. 3. In the rostral part of the septal component of the diagonal band of Broca the field pattern was more complex, containing, in addition to N1 and P1, further negative waves, N2 and N3. N2 was compounded of antidromically and synaptically evoked components and N3 was associated with monosynaptic excitation of the cells. 4. Stimulation of the lateral margin of the fornix was shown to excite antidromically and synaptically the same cells as were excited by stimulation of the medial aspect of the fornix. 5. Stimulation of the medial and lateral aspects of contralateral fornix generated positive waves of similar character to P1. 6. Intracarotid injection of hyperosmotic saline solution caused behavioural signs of arousal and inhibition of spontaneous discharge in a third of the units tested. Spontaneously discharging units (mean frequency +/- S.E. of mean, 13.4 +/- 1.8, n = 55) were inhibited by stimulation of the medial and lateral ipsilateral and contralateral fornix. It is suggested that inhibitory interneurones receive contra- and ipsilateral input. Units with these characteristics were found. 7. The septal component of the diagonal band of Broca was compared with other septal nuclei and found to resemble them in its rostral portion in that it has a reciprocal relationship with ventral and dorsal hippocampus. The caudal portion is unique in the cells project to dorsal and ventral hippocampus but there is no reciprocal projection.

Animals↗

PubMed1993

Norepinephrine injections in diagonal band of Broca selectively reduced the activity of vasopressin supraoptic neurons in the rat.

In the rat, transient drug-induced elevations of arterial blood pressure, which are sufficient to activate peripheral baroreceptors, produce a brief and selective cessation in the spontaneous activity of vasopressin-secreting cells in the hypothalamic supraoptic nucleus. This response appears to require the noradrenergic innervation of the diagonal band of Broca. The present study evaluated whether injections of norepinephrine into the diagonal band of Broca affect the spontaneous activity of supraoptic vasopressin-secreting neurons. Extracellular recordings were obtained from antidromically identified supraoptic neurons in pentobarbital anesthetized rats using a transpharyngeal approach. Injections of 200 nl of 10 microM norepinephrine into the diagonal band of Broca region arrested the spontaneous activity of 80% (12/15) of vasopressin-secreting neurons but only 7% (1/14) of oxytocin secreting-neurons demonstrated a comparable decrease in excitability. Vehicle injections did not influence the activity of any of the neurons tested. These results are consistent with the hypothesis that the baroreceptor-sensitivity of vasopressin neurons is mediated by a noradrenergic mechanism in the diagonal band of Broca.

Action Potentials↗

PubMed1997

Acute hypertension increases norepinephrine release in the diagonal band of Broca.

In vivo microdialysis was used to measure extracellular concentrations of norepinephrine in the diagonal band of Broca (DBB) during changes in blood pressure in conscious rats. Dialysate norepinephrine concentration was significantly increased during acute hypertension (280 +/- 40% of control), but was not changed by hypotensive hemorrhage. These results are consistent with the proposal that noradrenergic innervation of the DBB is selectively activated by increased blood pressure.

Acute Disease↗

PubMed1992

The development of neurons in the nuclei of the horizontal and vertical limb of the diagonal band of Broca of the rat: a qualitative and quantitative analysis of Golgi preparations.

We have studied the morphological alterations of neurons in the nuclei of the horizontal (NHL) and vertical (NVL) limbs of the diagonal band of Broca of rats from late embryonic life to maturity using the Golgi-Stensaas and Golgi-Cox methods. During late embryonic life and in the first postnatal days, the two nuclei of the diagonal band of Broca were found to be located near the ventral surface of the brain. Shortly thereafter, neurons in the NHL and NVL gradually take up the positions which they normally occupy in adulthood. At this stage neurons were small with round or elongated somata and 1-3 primary dendrites that only occasionally bore spines and very seldom showed varicosities, features commonly shown by neurons at later postnatal ages. At birth, cells showing varying soma shapes and dendritic morphology were present, and by postnatal day 4 (P4) the three forms of neurons previously described in adult rats (Dinopoulos et al., J. Comp. Neurol., 272 (1988) 461-474) were readily distinguished. During the second postnatal week, the size of cell somata as well as the number, size and extent of dendritic branching underwent considerable increases in both nuclei and at P14 neurons showed features typical of their adult counterparts. In addition they showed a dramatic increase in the number of spines which was followed during the next 10 days by a substantial decrease. Overall, the dendritic geometry of neurons in the NHL and NVL did not change significantly after P14, although their cell bodies continued to increase in size until the middle of the fourth and fifth postnatal weeks respectively. These findings suggest that neurons in the nuclei of the diagonal band of Broca show continuous growth from embryonic life to the end of the second postnatal week when they acquire morphological features comparable to the adult. Thereafter they exhibit only minor morphological alterations with the exception of extensive spine elimination which is pronounced during the third postnatal week and continues until adulthood.

Animals↗

PubMed1999

Electrical stimulation of the horizontal limb of the diagonal band of broca modulates population EPSPs in piriform cortex.

Electrical stimulation of the horizontal limb of the diagonal band of Broca (HDB) was coupled with recording of evoked potentials in the piriform cortex. Stimulation of the HDB caused an enhancement of the late, disynaptic component of the evoked potential elicited by stimulation of the lateral olfactory tract but caused a suppression of the synaptic potential elicited by stimulation of the posterior piriform cortex. The muscarinic antagonist scopolamine blocked both effects of HDB stimulation. The enhancement of disynaptic potentials could be due to cholinergic depolarization of pyramidal cells, whereas the suppression of potentials evoked by posterior piriform stimulation could be due to presynaptic inhibition of intrinsic fiber synaptic transmission by acetylcholine.

Animals↗

PubMed1989

Cholinergic and peptidergic projections from the medial septum and the nucleus of the diagonal band of Broca to dorsal hippocampus, cingulate cortex and olfactory bulb: a combined wheatgerm agglutinin-apohorseradish peroxidase-gold immunohistochemical study.

We have examined the distribution pattern and the density of various neuropeptide, neurotransmitter and enzyme containing neurons in the rat medial septum and the nucleus of the diagonal band of Broca to assess their possible involvement in the septohippocampal, septocortical and septobulbar pathways. Immunohistochemical methods were combined with the retrograde transport of a protein-gold complex injected in the hippocampus, the cingulate cortex or the olfactory bulb. Cholinergic neurons were the most numerous. Galanin-positive neurons were about two or three times less numerous than cholinergic cells. Both these cell types had a similar location though the choline acetyl transferase-like immunoreactive cells extended more caudally in the horizontal limb of the nucleus of the diagonal band of Broca. Immunoreactive cells for other neuroactive substances were few (calcitonin gene-related peptide, luteinizing hormone releasing hormone. [Met]enkephalin-arg-gly-leu) or occasional (dynorphin B, vasoactive intestinal polypeptide, somatostatin, neurotensin, cholecystokinin, neuropeptide Y and substance P). No immunoreactive cells for bombesin, alpha atrial natriuretic factor, corticotropin releasing factor, 5-hydroxytryptamine, melanocyte stimulating hormone, oxytocin, prolactin, tyrosine hydroxylase or arg-vasopressin were present. Choline acetyltransferase- and galanin-like immunoreactive cells densely participate to septal efferents. Cholinergic neurons constituted the bulk of septal efferent neurons. Galanin-positive cells were 22% of septohippocampal, 8% of septocortical, and 9% of septobulbar neurons. Galanin containing septohippocampal neurons were found in the medial septum and the nucleus of the diagonal band of Broca; galanin-positive septobulbar and septocortical cells were limited to the nucleus of the diagonal band of Broca. Occasional double-labellings were noticed with some peptides other than galanin. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were the most often observed; some other projecting cells stained for vasoactive intestinal polypeptide or dynorphin B. Luteinizing hormone-releasing hormone, calcitonin gene-related peptide and enkephalin were observed in septohippocampal neurons; luteinizing hormone-releasing hormone and vasoactive intestinal peptide were observed in septocortical neurons and calcitonin gene-related peptide, luteinizing hormone-releasing hormone and dynorphin B were observed in septo-bulbar cells. These results show that, in addition to acetylcholine, galanin is a major cellular neuroactive substance in septal projections to the hippocampus, the cingulate cortex and the olfactory bulb. The presence of septal projecting neurons immunoreactive for other peptides shows that a variety of distinct peptides may also participate, but in a smaller number, to septal efferent pathways.

Animals↗

PubMed1990

Neuronal responses related to the novelty and familarity of visual stimuli in the substantia innominata, diagonal band of Broca and periventricular region of the primate basal forebrain.

This study examined correlates of memory processes in neuronal activity recorded from the substantia innominata, the diagonal band of Broca and the periventricular region or the basal forebrain of monkeys performing recognition and/or visual discrimination tasks. Two types of neurons were found that responded differentially to stimuli on the basis of their novelty or their familiarity. Neurons (5/572) in the periventricular region rostral to the thalamus and caudal to the anterior commissure responded to familiar stimuli with increases in firing rate. Neurons in the substantia innominata (16/1058) and in the diagonal band (14/489) responded maximally to novel stimuli, with smaller responses to reappeared presentations of these stimuli. The properties of these two types of neurons were similar in three respects: (1) the magnitude of the differential response to novel and familiar presentations of stimuli were largest for stimuli presented on successive trials, and were attenuated for stimuli that had not been seen for some intervening trials; (2) both types of neurons responded to highly familiar stimuli as if they were novel if they had not been recently seen; (3) both types responded to two- and three-dimensional stimuli; and were recorded in rhesus monkeys trained on the recognition tasks and in untrained cynomolgus monkeys. An injection of HRP into the periventricular region of one monkey resulted in retrograde labeling of ventromedial regions of the prefrontal, cingulate and temporal cortices, of the amygdala, medial thalamus, supramammillary region of the midbrain. These data indicate that information about the novelty, familiarity or recency of presentation of visual stimuli is reflected in the responses of some basal forebrain neurons. Neurons in the substantia innominata and diagonal band of Broca could not be distinguished using the battery of applied tests, suggesting functional mechanisms common to both regions. The results of the anatomical experiment suggest that ventromedial limbic cortical and subcortical regions projecting to or through the periventricular region may be important for the transmission of information about visual stimuli and for memory function.

Action Potentials↗

PubMed1975

Medial forebrain bundle projections to the nucleus of the diagonal band of Broca.

The electrophysiological characteristics of the medical forebrain bundle (MFB) projections to the nucleus of the diagonal band of Broca (nDBB) were studied in acutely prepared cats. MFB stimulation evoked field potentials which consisted of a large negative wave followed by a shallow positivity. Extracellular unitary discharges appeared out of the negativity. In addition, intracellularly recorded EPSPs showed no significant shift in the latency to onset with changes in stimulus intensity. These observations indicate that at least some of the MFB projections to the nDBB are excitatory with respect to their target cells.

Action Potentials↗