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PubMed2006

Thyroidectomy alters the daily pattern of expression of the clock protein, PER2, in the oval nucleus of the bed nucleus of the stria terminalis and central nucleus of the amygdala in rats.

A role for thyroid hormones in the regulation of the rhythmic expression of circadian clock genes is suggested by the finding that surgical removal of the thyroid gland alters circadian behavioral and endocrine rhythms in rodents. Virtually nothing is known about the role of thyroid hormones in the regulation of clock genes responsible for the generation of circadian rhythmicity. To study this issue, we assessed in rats the effect of thyroidectomy/parathyrodectomy (TPX) on the expression of the clock protein, PER2, in the suprachiasmatic nucleus (SCN), the master circadian clock, and in a number of key limbic forebrain structures, the oval nucleus of the bed nucleus of the stria terminalis (BNSTov), the central nucleus of the amygdala (CEA), the basolateral amygdala (BLA) and the dentate gyrus (DG). TPX significantly altered the normal daily pattern of PER2 expression in the BNSTov and CEA, but had no effect on PER2 expression in the SCN, BLA and DG. Thus, although thyroid hormones modulate PER2 expression in the brain, the effect is tissue specific and therefore likely not to be mediated by a direct effect of the hormone on gene expression.

Amygdala↗

PubMed1997

The pedunculopontine tegmental nucleus issues collaterals to the fastigial nucleus and rostral ventrolateral reticular nucleus in the rat.

The pedunculopontine-laterodorsal tegmental nuclear complex was identified as a major source of brainstem afferents terminating in the fastigial cerebellar nucleus and/or ventrolateral reticular nucleus (n.Rvl). Collaterals from the pedunculopontine nucleus (Ch5 area) to rostral [vasopressor] regions of the fastigial nucleus and ventral reticular formation were revealed with a combined retrograde tracing technique. The data implicate acetylcholine as a transmitter and raise the hypothesis that the identified afferents may contribute to the autonomic and behavioral responses to midline cerebellar stimulation.

Afferent Pathways↗

PubMed1989

Projections of the nucleus of the optic tract to the nucleus reticularis tegmenti pontis and prepositus hypoglossi nucleus in the pigmented rat as demonstrated by anterograde and retrograde transport methods.

The visual pathways from the nucleus of the optic tract (NOT) to the nucleus reticularis tegmenti pontis (NRTP) and prepositus hypoglossi nucleus (ph) were studied following injections of tritiated leucine into the NOT of pigmented rats. The cell bodies of origin of the pretectal-NRTP, NRTP-ph, and pretectal-ph projections were determined using retrograde horseradish peroxidase (HRP) technique. The pretectum projects strongly to the rostral two-thirds of the central and pericentral subdivisions of the NRTP and sends a remarkably smaller projection to the ph. Both are entirely ipsilateral. The fibers destined for the ph travel with the NOT-NRTP bundle, pass through the NRTP, traverse the medial longitudinal fasciculus, and are distributed to the rostral one-half of the ph. The retrograde HRP studies confirm these pathways. The pretectal projections to the NRTP arise from neurons in the rostromedial NOT; those to the ph are located primarily in the rostral NOT although small numbers are found within the anterior, posterior, and olivary pretectal nuclei. Of major importance is the fact that the ph injections retrogradely label neurons within the NRTP and the adjacent paramedian pontine reticular formation. This NRTP-ph projection is entirely bilateral and arises from parts of both subdivisions of the nucleus targeted by NOT afferents. Both the direct NOT-ph and indirect NOT-NRTP-ph connections provide the anatomical basis for the relay of visual (optokinetic) information to the perihypoglossal complex and, presumably, by virtue of reciprocal ph-vestibular nuclear connections, to the vestibular nuclei itself. Such pathways confirm previous physiological studies in rat and, in particular, clarify the contrasting effects of electrolytic lesions of NRTP in rat which completely abolishes optokinetic nystagmus (OKN) (Cazin et al., 1980a) vs kainic acid lesions which produce only minor effects on OKN slow velocity (Hess et al., 1988). Given these differential effects, one concludes that the critical pathway for OKN passes in relation to, but is not significantly relayed by, the neurons of the NRTP or adjacent pontine tegmentum. The present studies suggest that one such fiber system is the NOT-ph bundle. How this relatively small projection compares to other possible fiber of passage systems remains to be determined electrophysiologically.

Animals↗

PubMed1994

Effects of corticosterone on CRH mRNA and content in the bed nucleus of the stria terminalis; comparison with the effects in the central nucleus of the amygdala and the paraventricular nucleus of the hypothalamus.

We previously reported that corticosterone (CORT) increased corticotropin-releasing hormone (CRH) mRNA in the central nucleus of the amygdala (CEA), while reducing it in the paraventricular nucleus (PVN) of the hypothalamus by using in situ hybridization histochemistry. The bed nucleus of the stria terminalis (BNST) is closely related to the amygdala, and it is also a source of extrahypothalamic CRH; therefore, we examined CRH mRNA changes in the BNST following systemic treatment with CORT in adrenally-intact rats. Effects of adrenalectomy on CRH mRNA in the BNST, PVN and CEA were also examined. In addition, CRH content in these nuclei and in the median eminence (ME) were determined by micropunch dissection technique combined with CRH radioimmunoassay in CORT pellet implanted rats. Subcutaneous injections of high CORT (5 mg/day, over 14 days) increased CRH mRNA in the dorsal part of the lateral BNST (BSTLD) at 2, 4 and 8 days, although the low dose of CORT (1 mg/kg/day) had no significant effects. By contrast, in the ventral part of the BNST (BSTV) neither the high nor low dose of CORT altered CRH mRNA levels. In a second experiment, a slowly-releasing CORT pellet (200 mg, 60-day release) produced an elevation of CRH mRNA at both 1 and 2 weeks or at 1 week in the BSTLD or in the BSTV, respectively. These results show that glucocorticoids can facilitate CRH mRNA expression in the BSTLD in the same manner as seen in the CEA, and that CRH mRNA in the BSTLD can respond to CORT more than in the BSTV. In a third experiment, bilateral adrenalectomy, however, did not affect CRH mRNA in the BNST although there was a modest decrease in the CEA and a robust increase in the PVN. Finally, in CORT pellet (200 mg, for 2 weeks) implanted rats, CRH content in the ME significantly decreased and modestly increased in the CEA compared with control rats, whereas it did not change in the PVN and BNST. Taken together, these results suggest that (1) CRH in the BNST and the CEA may share some common functions in neuroendocrine and behavioral changes, but that (2) mechanisms of CRH synthesis or its releasing sites may be different in the BNST and CEA.

Amygdala↗

PubMed1994

An indirect projection from the nucleus of the solitary tract to the central nucleus of the amygdala via the parabrachial nucleus in the rat: a light and electron microscopic study.

The morphological basis of how visceral information from the nucleus of the solitary tract (NTS) is relayed from the parabrachial nucleus (PBN) to the central nucleus of the amygdala (Ce) was studied at the light and electron microscopic levels using the anterograde tracer, Phaseolus vulgaris leucoagglutinin (PHA-L), kainic acid degeneration, and retrograde tracing with horseradish peroxidase (HRP). After injection of PHA-L into the caudal NTS, anterogradely labeled fibers and terminals were predominantly distributed in the external lateral (el) and central lateral (cl) subnuclei of the PBN. After injection of HRP into the Ce, retrogradely labeled neurons in PBN were mainly distributed in the same areas. In double-labeling experiments, there was a clear overlap between neuronal elements labeled with HRP and PHA-L in the el and cl. At the electron microscopic level, the PHA-L-labeled axon terminals from the NTS mainly contained spherical agranular synaptic vesicles and formed asymmetric contacts with the postsynaptic dendrites or dendritic spines in PBN. After the lesioning agent kainic acid was injected into the NTS and HRP deposited in the Ce, it was found the afferent fibers from the NTS made direct synaptic contact with the lateral PBN neurons which in turn projected to Ce. Such evidence adds to our growing knowledge of regulation of visceral function in central nervous system and would be likely helpful for understanding the important roles of the NTS, PBN and Ce in the central control of cardiovascular, respiratory and gastrointestinal functions.

Amygdala↗

PubMed1991

Fiber outgrowth from fetal vasopressin neurons of the suprachiasmatic nucleus, bed nucleus of the stria terminalis, and medial amygdaloid nucleus transplanted into adult Brattleboro rats.

Outgrowth of fibers from different types of vasopressin (AVP) neurons was compared in the brains of AVP-deficient Brattleboro rats. Fetal grafts of the suprachiasmatic nucleus (SCN), the bed nucleus of the stria terminalis (BST), and the medial amygdaloid nucleus (MA) were implanted into the lateral ventricle. AVP-immunoreactive fibers from all grafts entered the host tissue in the lateral septum. SCN fibers were confined to the lateral margin of the septum. In contrast, MA and BST fibers formed equally dense networks spanning the width of the lateral septum. The data suggest that these transplanted neurons show specific outgrowth, and that the phylogenetically related BST and MA neurons follow similar cues to reach their targets.

Amygdala↗

PubMed2005

Nocifensive reflex-related on- and off-cells in the pedunculopontine tegmental nucleus, cuneiform nucleus, and lateral dorsal tegmental nucleus.

Cholinergic projections from the pedunculopontine tegmental nucleus (PPTg) to the rostral ventromedial medulla (RVM) have been implicated in nociceptive modulation. The goal of this study was to identify neurons with nocifensive reflex-related activity in the mesopontine tegmentum including the PPTg. This study used the same behavioral neurophysiological classification system to identify neurons as has been extensively described in the RVM. Extracellular microelectrode recording was conducted in lightly anesthetized rats. Changes in firing associated with the noxious heat-evoked tail flick reflex were used to classify neurons as "on-cells" (displayed a burst in neuronal activity associated with the reflex), "off-cells" (displayed a pause in activity), and neutral cells (showed no response). Of 188 neurons studied in 23 rats, 77 were classified as on-cells, 14 as off-cells, the remainder as neutral cells. Recordings during periods without noxious stimulation found that some of the on- and off-cells displayed spontaneous transitions between active and silent periods termed cell cycling. The distribution of on- and off-cells in the mesopontine tegmentum overlapped and included the cholinergic PPTg and lateral dorsal tegmental nucleus identified by NADPH diaphorase staining, as well as the cuneiform nucleus and periaqueductal gray. The mesopontine tegmentum thus contains nocifensive reflex-related neurons with neurophysiological characteristics similar to those reported in the RVM. Neurons showing reflex-related activity were frequently encountered in the cholinergic PPTg and LDTg. Further studies will be required to determine whether these neurons modulate nociception through a link to the RVM.

Acetylcholine↗

PubMed2006

Sex-specific densities of estrogen receptors alpha and beta in the subnuclei of the nucleus tractus solitarius, hypoglossal nucleus and dorsal vagal motor nucleus weanling rats.

In rats ventilatory responses to N-methyl-d-aspartate (NMDA) receptor modulation are sexually dimorphic and may be altered by manipulating brain levels of estrogen receptors. Here we used image analysis and immunohistochemistry in weanling male and female rats to quantitate areas and densities of ER alpha and ER beta-positive neurons within medullary regions associated with cardiopulmonary regulation including the hypoglossal nucleus, subnuclei of the nucleus of the solitary tract (NTS), and the dorsal motor nucleus of the vagus. Weanling rats were selected because ventilation, metabolic rate, and body and brain weights are comparable at this age and there are no large fluctuations in plasma hormone levels. Females, relative to males, had smaller areas in the A2 region and parts of the NTS. Counts and densities for ER alpha were greater in females than males in almost all regions studied. In contrast sex differences in ER beta were found in fewer nuclei, but in those higher counts and densities were noted in females. In general, ER beta-positive neurons in the brainstem regions examined were less prevalent than ER alpha neurons. Thus, in weanling rats sex affected ER alpha and ER beta neuronal densities in brainstem regions associated with cardiopulmonary regulation that may be responsible for sex differences in control of breathing.

Analysis of Variance↗

PubMed1999

Projections from subnucleus oralis of the spinal trigeminal nucleus to contralateral thalamus via the relay of juxtatrigeminal nucleus and dorsomedial part of the principal sensory trigeminal nucleus in the rat.

Following injection of HRP into contralateral thalamus, retrogradely labeled cells were observed in principal sensory trigeminal nucleus (Vp) and an area of juxtatrigeminal nucleus (JX) formerly described by John and Tracey (1987). When PHA-L was delivered to dorsomedial part of the subnucleus oralis (Vodm), PHA-L labeled terminals were seen in dorsomedial part of the Vp (Vpdm) and in the JX region. Comparing the distribution of PHA-L labeled terminal field with that of HRP labeled JX neurons showed that the labeled terminals and neurons were overlapped closely in the JX. The distribution patterns of the labeled terminals and JX neurons were also the same: viewed on the coronal planes caudal-rostrally, both of the labelings began to appear at the levels where the facial nerve root was just broken. Rostrally, at middle levels of the motor trigeminal nucleus (Vmo), the labelings showed their typical view covering dorsal and ventral JX (dJX, vJX). The labelings disappeared at rostral poles of the Vmo and Vp. When injections of PHA-L into the Vodm and HRP into the contralateral thalamus was made in one rat, the contacts between Vodm projecting terminals labeled with PHA-L and HRP labeled trigemino-thalamic neurons were seen in the JX and also in the Vpdm. Then, electron microscopic (EM) study was done, injections of kainic acid into the Vodm and HRP into the contralateral thalamus was performed simultaneously. After EM embedding, the JX and Vpdm regions were selected, ultrathin sections were cut and observed with EM. In both areas, axo-somatic and axo-dendritic synapses were seen between degenerated boutons and HRP labeled somata or dendrites. Namely, the Vodm projecting terminals synapsed on trigemino-thalamic neurons in the JX and Vpdm. Anyway, axo-dendritic synapses was the main type of observed synapses. Thus, the present work demonstrated 1. the JX containing a group of trigemno-thalamic neurons was a target of special projections froin the Vodm; 2. The Vodm neurons projected to the contralateral thalamus through the relay of JX and Vpdm neurons.

Animals↗

PubMed1984

[Antidromic and synaptic potentials of neurons of the lateral vestibular nucleus of the cat evoked by stimulation of the interstitial nucleus of Cajal and the nucleus of Darkschewitsch].

Effects of stimulation of the Cajal interstitial nucleus and Darkschewitsch nucleus on the activity of neurons of the lateral vestibular nucleus of Deiters was studied in experiments on cats anesthetized with nembutal. It was shown that stimulation of the mentioned structures lead to antidromic and synaptic activation of Deiters neurons. Ascending axon collaterals of vestibular neurons to the marked brain stem structures were revealed. Stimulation of both Cajal and Darkschewitsch nuclei evoked mono- and polysynaptic EPSP and IPSP in Deiters neurons. The convergence of influences from both nuclei on the investigated neurons was shown. Peculiarities and functional significance of the indicated influences are discussed.

Animals↗

PubMed1986

Different pharmacological anatomy in the paraventricular hypothalamic nucleus, supraoptic nucleus, and suprachiasmatic nucleus of rats: quantitative autoradiography on angiotensin II receptor binding sites.

Angiotensin II (AII) and vasopressin (VP) play important roles in cardiovascular function. Using 125I-[Sar1,Ile8]-angiotensin II (125I-SI-AII), a potent AII antagonist, AII receptor binding sites were autoradiographically localized in three VP-producing areas of the hypothalamus and compared in hypertensive and normotensive rats. Within three major VP-producing areas, AII receptor binding was highest in the paraventricular hypothalamic nucleus and lowest in the supraoptic nucleus, suggesting that a differential AII regulation of separate VP systems exists in the brainstem. No statistical difference in 125I-SI-AII receptor binding was found between WKY and SHR rats in each of the three major VP-producing nuclei studied. These results are consistent with a role of AII receptors in a subtle and complicated regulation of VP in cardiovascular function.

Angiotensin II↗

PubMed2002

Cortical projections to the nucleus of the optic tract and dorsal terminal nucleus and to the dorsolateral pontine nucleus in macaques: a dual retrograde tracing study.

The nucleus of the optic tract and dorsal terminal nucleus of the accessory optic system (NOT-DTN) along with the dorsolateral pontine nucleus (DLPN) have been shown to play a role in controlling slow eye movements and in maintaining stable vision during head movements. Both nuclei are known to receive cortical input from striate and extrastriate cortex. To determine to what degree this cortical input arises from the same areas and potentially from the same individual neurons, we placed different retrograde tracers into the NOT-DTN and the DLPN. In the ipsilateral cortical hemisphere the two projections mainly overlapped in the posterior part of the superior temporal sulcus (STS) comprising the middle temporal area (MT), the middle superior temporal area (MST), and the visual area in the fundus of the STS (FST) and the surrounding cortex. In these areas, neurons projecting to the NOT-DTN or the DLPN were closely intermingled. Nevertheless, only 3-11% of the labeled neurons in MT and MST were double-labeled in our various cases. These results indicate that the cortical input to the NOT-DTN and DLPN arises from largely separate neuronal subpopulations in the motion sensitive areas in the posterior STS. Only a small percentage of the projection neurons bifurcate to supply both targets. These findings are discussed in relation to the optokinetic and the smooth pursuit system.

Animals↗

PubMed1983

The postnatal metabolic development of the nucleus commissuralis and nucleus medialis of the nucleus tractus solitarius.

The ontogeny of the metabolic requirements in the nucleus commissuralis (NC) and nucleus medialis (NM) of the nucleus tractus solitarius was studied in the postnatal rat using the [3H]2-deoxy-D-glucose autoradiography technique. It was found that the metabolic requirements in the NC and NM are not constant between 2 and 12 weeks of age. A high level of metabolic activity at 2 and 8 weeks is contrasted by a lower level at 4 and 12 weeks. The apparent changes in metabolic requirements are not related to the changes in blood pressure of the rats or neuronal densities of the subnuclei which occur as the rats mature, or to exchange vessel densities of the subnuclei. Thus the higher energy requirements of the NC and NM at 2 and 8 weeks of age suggest that developmental and/or functional processes are more active at these stages.

Animals↗

PubMed2001

Collateral projections of nucleus raphe dorsalis neurones to the caudate-putamen and region around the nucleus raphe magnus and nucleus reticularis gigantocellularis pars alpha in the rat.

It was examined whether or not the nucleus raphe dorsalis (RD) neurons projecting to the caudate-putamen (CPu) might also project to the motor-controlling region around the nucleus raphe magnus (NRM) and nucleus reticularis gigantocellularis pars alpha (Gia) in the rat. Single RD neurons projecting to the CPu and NRM/Gia by way of axon collaterals were identified by the retrograde double-labeling method with fluorescent dyes, Fast Blue and Diamidino Yellow, which were injected respectively into the CPu and NRM/Gia. Then, serotonin (5-HT)-like immunoreactivity of the double-labeled RD neurons was examined immunohistochemically; approximately 60% of the double-labeled RD neurons showed 5-HT-like immunoreactivity. The results indicated that some of serotonergic and non-serotonergic RD neurons might control motor functions simultaneously at the levels of the CPu and NRM/Gia by way of axon collaterals.

Amidines↗

PubMed1987

Synaptic reorganization in the medial amygdaloid nucleus after lesion of the accessory olfactory bulb of adult rat. II. New synapse formation in the medial amygdaloid nucleus by fibers from the bed nucleus of the stria terminalis.

The rearrangement of terminations from the bed nucleus of stria terminalis (BST) was examined in the medial amygdaloid nucleus (MAN) at 2 months following the lesion of the accessory olfactory bulb (AOB) using an electron microscopy and degeneration study. At 2 days following a BST lesion, the number of degenerating synapses was 0.7 +/- 0.1 (mean +/- S.E.M.) per unit area (2500 microns2) in the molecular layer, and 3.0 +/- 0.3 in the cellular part. At 2 months after an AOB lesion, the degenerating synapses from the AOB had completely disappeared from the MAN. The BST was then lesioned at 2 months after the AOB lesion and, at 2 days following this BST lesion, the degenerating synapses were counted in MAN. The numbers observed were 3.3 +/- 0.6 per unit area in the molecular layer and 4.5 +/- 0.4 in the cellular part. Therefore, the number of these degenerating synapses increased significantly within the molecular layer, though, in the cellular part the number of synapses was not significantly elevated over control. No differences in postsynaptic profiles (ratio of synapses on dendritic spine to dendritic shaft) were observed after the AOB lesion. These results indicate that the BST fibers formed new synapses in the molecular layer following the denervation of AOB fibers. The possibility of new synapse formation by other afferent fibers in addition to the AOB fibers is discussed as is the relationship between lesion induced synaptic reorganization and functional recovery after injury.

Amygdala↗

PubMed1995

Simultaneous single unit recording in the medial nucleus of the medial geniculate nucleus and amygdaloid central nucleus throughout habituation, acquisition, and extinction of the rabbit's classically conditioned heart rate.

The present study examined single neuron activity in the medial nucleus of the medial geniculate (mMG) and amygdaloid central nucleus (ACe) simultaneously across several phases of differential heart rate conditioning (habituation, acquisition, and extinction). Within the same animals, the magnitude of mMG and ACe unit responses to two tone conditioned stimuli (CS) exhibited habituation, differential acquisition, and extinction. Neurons in each area developed a differential response latency to the CSs during acquisition, suggesting that mMG and ACe may be involved in changes of synaptic efficacy. Units in both areas rapidly developed a differential response magnitude to the CSs (< 6 acquisition trials), however, mMG units responded to the CSs with a shorter latency than ACe units across all phases of training. This suggests that unlearned and learned CS information may access mMG before ACe. These results are consistent with the notion that conditioning-induced plasticity which occurs in mMG may influence the conditioning-induced plasticity that occurs further downstream in the amygdala.

Acoustic Stimulation↗

PubMed1994

Chemically defined collateral projections from the pons to the central nucleus of the amygdala and hypothalamic paraventricular nucleus in the rat.

Triple fluorescence labelling was employed to reveal the distribution of chemically identified neurons within the pontine laterodorsal tegmental nucleus and dorsal raphe nucleus which supply branching collateral input to the central nucleus of the amygdala and hypothalamic paraventricular nucleus. The chemical identity of neurons in the laterodorsal tegmental nucleus was revealed by immunocytochemical detection of choline-acetyltransferase or substance P; in the dorsal raphe nucleus, the chemical content of the neurons was revealed with antibody recognizing serotonin. The projections were defined by injections of two retrograde tracers, rhodamine- and fluorescein-labelled latex microspheres, in the central nucleus of the amygdala and paraventricular nucleus, respectively. Neurons projecting to both the central nucleus of the amygdala and the paraventricular nucleus were distributed primarily within the caudal extensions of the laterodorsal tegmental nucleus and dorsal raphe nucleus. Approximately 11% and 7% of the labelled cells in the laterodorsal tegmental nucleus and dorsal raphe nucleus projected via branching collaterals to the paraventricular nucleus and central nucleus of the amygdala. About half of these neurons in the laterodorsal tegmental nucleus were cholinergic, and one-third were substance-P-ergic; in the dorsal raphe nucleus, approximately half of the neurons containing both retrograde tracers were serotonergic. These results indicate that pontine neurons may simultaneously transmit signals to the central nucleus of the amygdala and paraventricular nucleus and that several different neuroactive substances are found in the neurons participating in these pathways. This coordinated signalling may lead to synchronized responses of the central nucleus of the amygdala and paraventricular nucleus for the maintenance of homeostasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdala↗

PubMed1989

Direct projections from the central amygdaloid nucleus to the hypothalamic paraventricular nucleus: possible role in stress-induced adrenocorticotropin release.

The amygdala, particularly the central amygdaloid nucleus, is important for the expression of adrenocorticotropin and corticosterone responses during stress. The aim of the present study was to determine if the central amygdaloid nucleus directly innervated the hypothalamic paraventricular nucleus. To accomplish this aim, the Phaseolus vulgaris leucoagglutinin lectin anterograde tracing method was used. Injections of the tracer into the medial central amygdaloid nucleus resulted in axonal and terminal labeling within the medial and lateral parvocellular parts of the caudal paraventricular nucleus. A dense patch of labeling was observed within the lateral wing of the lateral part of the parvocellular paraventricular nucleus. Only a few labeled axons were observed within the paraventricular nucleus of animals that had lectin injections localized to the lateral part of the central nucleus. Tracer injections localized to the medial amygdaloid nucleus resulted in axonal and terminal labeling primarily within the anterior parvocellular and periventricular regions of the paraventricular hypothalamic nucleus. Sparse to moderate axonal and terminal labeling was observed within the magnocellular parts of the paraventricular nucleus in animals that had injections of tracer into either the medial central nucleus or the medial nucleus. No labeling was observed within the paraventricular nucleus of animals that had injections of lectin within other amygdaloid nuclei or adjacent regions of the striatum. The results demonstrated a topographically organized projection from the amygdala to the hypothalamic paraventricular nucleus. The central nucleus mainly innervates the caudal lateral and medial parvocellular paraventricular nucleus. The medial nucleus innervates the rostral parvocellular parts of the paraventricular nucleus. These pathways could form the anatomical substrates of amygdaloid modulation of neuroendocrine responses to stressors.

Adrenocorticotropic Hormone↗