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C Batini

Publications and source records attributed to C Batini.

At least 19 recordsLinked to original sources
PubMed1992

Pattern of electroencephalographic activity during light induced seizures in genetic epileptic chicken and brain chimeras.

Genetic epilepsy was studied in Fayoumi epileptic (F.Epi) chickens and in neural chimeras obtained by selective substitution of embryonic brain vesicles of F.Epi donors in normal recipient chickens. Typical motor seizures accompanied by convulsions were evoked by intermittent light stimulation in F.Epi and in chimeras having embryonic substitution of the prosencephalon and the mesencephalon. The motor seizure was less severe in chimeras receiving only the prosencephalon. In the F.Epi, as well as in all the chimeras, the EEG during seizures was characterized by a desynchronized (or a flattening) pattern of activity. F.Epi and chimeras had a lower threshold to Metrazol induced seizures than control chickens. The experimental animals show that, in this model, large prosencephalic and mesencephalic areas are involved in the epileptic disease. The epileptic character of this genetic dysfunction is discussed.

Animals↗
PubMed1992

Cerebellar nuclei and the nucleocortical projections in the rat: retrograde tracing coupled to GABA and glutamate immunohistochemistry.

The amino acids GABA and glutamate (Glu) are thought to be the principal substances in the central nervous system responsible for neuronal inhibition and excitation. Their distributions among the different neurons in a defined pathway may thus be indicative of the contributions of the cells to pathway function. Examples of such neurons are those of the cerebellar nuclei which, while regulating output from the Purkinje cells of the cerebellar cortex, are also found to project back to the cerebellar cortex. Immunohistochemical experiments were done to identify GABA and glutamate (Glu) containing cells in the adult rat cerebellar nuclei. Consecutive semithin and serial vibratome sections were incubated with antisera raised in rabbit against GABA and Glu. In semithin sections, only small neurons were intensely GABA immunoreactive (GABA-IR) (31.7%), and the majority (80.5%) were Glu immunoreactive (Glu-IR) of different sizes. Consistent with Glu being a metabolic precursor for GABA, 75.4% of the GABA-IR population colocalized Glu. In vibratome sections GABA-IR neurons showed some local differences in number, whereas the Glu-IR were uniformly distributed in the three nuclei studied. Measured mean diameters for these neurons showed a distinct size difference for the GABA- and Glu-IR with little overlap. Cerebellar nuclei neurons projecting to the cortex (nucleocortical neurons, NCN) were identified by locally preinjecting the retrograde transported WGA-apoHRP-colloidal gold complex in the cerebellar cortex. Vibratome sections of these cerebellar were silver intensified for the retrograde tracer and double labeled for GABA and Glu. Of the total number of identified NCN, 8.7% were GABA-IR (10 animals) and 47.7% Glu-IR (5 animals). Many retrograde labeled NCN in the core of the thick sections were immunonegative for both amino acids due to poor antibody penetration, thus underestimating the proportions of cells containing GABA and Glu. The size distributions for the GABA-IR and Glu-IR NCN were similar to those measured in non-retrograde labeled nuclei in thick sections. The conclusions reached are that GABA-IR neurons of the cerebellar nuclei, including the NCN, use GABA as the presumed inhibitory neurotransmitter and that Glu-IR neurons may use Glu or another excitatory neurotransmitter.

Afferent Pathways↗
PubMed1992

Divalent cation changes in cerebellar Purkinje cells after climbing fiber deafferentation.

A secondary ion mass spectrometry (SIMS) microscope was used to detect intracellular stores of calcium, magnesium, sodium and potassium. Measurements were made in semithin sections of fixed tissues of normal and climbing fiber deafferented cerebellar cortex. Quantitative data were collected from 150 microns diameter image fields in the molecular and granule layers. The results indicate smaller quantities of both calcium and magnesium in the deafferented cerebellar cortex compared to the normals, the molecular as well as the granule layer being affected. The results are discussed in terms of the usefulness and limitations of the SIMS microscope for histological preparations.

Afferent Pathways↗
PubMed1991

The immunocytochemical distribution of calbindin-D28k and parvalbumin in identified neurons of the pulvinar-lateralis posterior complex of the cat.

The calbindin-D28k and parvalbumin immunoreactivities of the neurons of the pulvinar-lateral posterior complex (Pul-LP) were studied in the cat. The neurons of the Pul-LP projecting to the cerebral cortex were identified by a retrogradely transported tracer injected in the suprasylvian gyrus. Two populations of cells were found, a calbindin-D28k-immunoreactive, large-diameter population and a parvalbumin-immunoreactive, small-diameter group. The two kinds of cells are closely intermingled. The former includes the neurons retrogradely marked, and therefore projecting to the suprasylvian gyrus. The latter includes neurons which were not retrogradely marked, and therefore presumably intrinsic elements.

Animals↗
PubMed1991

Tetrodotoxin induced calcium spikes: in vitro and in vivo studies of normal and deafferented Purkinje cells.

Tetrodotoxin (TTX) is widely used to block the sodium dependent action potential in excitable cells to study their other ionic properties. TTX applied outside, selectively blocks voltage dependent sodium channels and is thought to have no other effects. We report here that TTX, applied to slices of rat cerebellum, suppressed sodium spikes of the Purkinje cells and induced firing in bursts of slower spikes. This activity was blocked by cobalt (2 mM) or cadmium (0.2 mM) in the medium as well as by hyperpolarizing currents showing that the slow spikes were due to voltage dependent calcium channels. The membrane potential was not significantly changed by TTX and the spikes during the bursts had the same threshold potentials and peak spike amplitudes as the voltage and Ca2+ dependent dendritic spikes evoked by injected current before adding TTX. This indicated that no marked changes in the membrane conductances were produced by the TTX. Unlike the burst firing induced by removing extracellular sodium, the TTX induced bursts were not followed by a large hyperpolarization. The same kind of results were obtained with extracellular recording in the in-vivo preparation with TTX applied topically or by pressure near the recording sites. TTX induced burst firing was not due to blocking afferent inhibitory input to the PC, since bicuculline (10(-6) M) applied without TTX, produced only increased firing of fast action potentials and no bursts. The bursts could be arrested within 1 to 2 min by intravenously administering 2 mg/kg sodium pentobarbital, the blockage lasted from 5 to 15 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1991

Decreased sensitivity of cerebellar nuclei neurons to GABA and taurine: effects of long-term inferior olive destruction in the rat.

The effects of iontophoretically applying the presumed Purkinje cell inhibitory neurotransmitters, GABA and taurine, were tested on neurons of the cerebellar nuclei in normal and in climbing-fiber-deafferented cerebella. Rats treated with 3-acetylpyridine to totally destroy the inferior olive were used for acute experiments 105-185 days after treatment. In controls, nearly all neuronal firing was dose-dependently depressed by both inhibitory amino acids. The depression in firing for both were antagonized by bicuculline and picrotoxin but not by strychnine while TAG specifically antagonized only responses to taurine. At sufficient doses, bicuculline and TAG induced disinhibitory responses (significant release of neuron discharge) in the absence of applied antagonist. In deafferented animals, the inhibitory efficacy of GABA and taurine were drastically reduced; most of the neurons failed to respond to these amino acids at the same iontophoretic parameters as for the control rats. Moreover, high doses of bicuculline and TAG did not induce any disinhibitory response (no significant increase in discharge rate) in most of the neurons tested. These results clearly demonstrate that climbing fiber deafferentation reduces postsynaptic sensitivity of the cerebellar nuclei neurons for the presumed Purkinje cell inhibitory neurotransmitters.

Action Potentials↗
PubMed1979

[Interaction between the vestibulo-ocular and the oculomotor systems].

Optomotor nystagmic activity has been elicited in the "encéphale isolé" cat during repetitive electric stimulation of selective oculomotor regions of the frontal cortex and superior colliculus. These regions were nystagmogenic only when facilitated by a cortical arousal or a vestibular activation.

Animals↗
PubMed1979

Interaction between the horizontal vestibulo-ocular reflex and optokinetic response in rabbits.

Dynamic characteristics of the horizontal vestibulo-ocular reflex (HVOR), the optokinetic response (OKR), and their interactions were investigated in alert albino rabbits. For stimulation of the horizontal semicircular canals, the whole rabbit was rotated sinusoidally on a motor-driven turntable at peak-to-peak amplitudes of 5 degrees to 30 degrees over a frequency range of 1/30 to 1/2 Hz. Optokinetic stimulation was provided by a narrow vertical slit light source presented in front of the eye to be tested. The evoked horizontal eye movements were observed and measured by means of a closed circuit television system adapted to provide an analog signal proportional to the eye movement. The net HVOR was obtained by rotation of the turntable in darkness and the net OKR by rotation of the light source. Combining rotation of the turntable with a stationary light source immediately increased the gain and reduced the phase shift of the HVOR. The light source moving in phase with the turntable, but at twice the angular amplitude, reduced the gain and advanced the phase of the HVOR. Eye movement curves of the HVOR modified by a fixed or moving slit light could be reconstructed approximately by a linear combination of the net HVOR and OKR.

Animals↗
PubMed1979

Olivo-cerebellar activity during harmaline-induced tremor.A 2-[14C]deoxyglucose study.

The specific neuronal activity of the olivo-cerebellar system of the cat under the effect of harmaline has been studied using the 2-[14C]deoxyglucose method. The results obtained in animals treated with tremogenic doses of harmaline, but immobilized with flaxedil, have been compared with those of non-treated controls. An increased radioactivity in specific regions of the olivo-cerebellar system including parts of the medial and dorsal accessory olive and the corresponding receiving molecular layer have been found. No involvement of the granule cell layer nor of the nuclear cells has been observed. It is therefore suggested that the tremogenic rhythmicity of the cerebellar output is organized uniquely by an increased climbing fiber input.

Alkaloids↗
PubMed1979

On the fibers of the III, IV and VI cranial nerves of the cat.

The fiber content and diameter spectra of the cranial nerves III, IV and VI were analysed in cat. A semi-automatic technique of measuring fiber diameters is presented and compared to the manual method. The number of fibres was counted in the proximal part of the three main nerves and in each of their distal branches before they enter the EOM. Compared to the muscle weight, the branch to the RB had fewer fibers than all the other muscle branches. The diameter spectra of the proximal part of the three main nerves were compared with the diameter spectra of each of their distal branches. Minor differences were found among them. Only the RB had a striking difference in the spectrum which was skewed toward the large diameters.

Abducens Nerve↗
PubMed1978

Brain stem nuclei giving fibers to lobules VI and VII of the cerebellar vermis.

The HRP method has been used to identify all the brain stem nuclei, which may project to lobule VI and/or VII of the posterior cerebellar vermis. Three tentative degrees of labeling of the different structures have been assigned: 'massive', 'clear' and 'discrete'. (1) Massive projections have been found to reach lobule VI and VII from the inferior olive and lobule VII only from the nucleus reticularis tegmenti pontis. (2) Clear projections have been found to reach lobule VI only from the pontine nuclei, the nucleus reticularis tegmenti pontis, the nucleus reticularis lateralis and the reticularis paramedianus; lobule VII only from the raphe nuclei, and both VI and VII from the perihypoglossal and vestibular nuclei. (3) Discrete projections have been found to reach lobule VI and VII from the deep cerebellar nuclei; lobule VI only from the nucleus tracti solitarii and nucleus cuneatus externus; lobule VII only from the nucleus lemnisci lateralis pars ventralis, the nuclei parabrachiales and the nucleus subcoeruleus.

Animals↗
PubMed1978

[Harmaline-induced tremor and cerebral activities: labeling with 14C-2-deoxyglucose in the rat].

The brain structures specifically involved in harmaline-induced tremor have been identified in the Rat by using the 14C-2-deoxyglucose marking Method. The results obtained in an animal treated with tremogenic doses of harmaline, but immobilized with Faxedil, have been compared with those of another animal, not treated, but submitted to the same experimental procedure. The most specifically marked structure was the inferior olive. Secondarily marked structures were the posterior part of the lateral reticular formation, the caudato-putamen area and the prefrontal and frontal cortex.

Alkaloids↗
PubMed1977

[Interaction between visual activation and proprioceptive activation in neurons of the superior colliculus].

Units located in the superficial and intermediate layers of the superior colliculus are activated by proprioceptive stimulation of the extraocular muscle nerves as well as by specific visual stimuli. Units of the deep layer of the colliculus, not sensitive to visual activation, are inhibited by proprioceptive stimulation. A few of the units showed interaction between the two types of stimulation, the proprioceptive response appearing only when spontaneous activity was decreased by a visual stimulus.

Animals↗