Electrophysiological responses to transient hypoxia were studied in neocortical brain slices from adult gerbils. Evoked responses and direct current (DC) potentials were recorded in layer III of the parietal cortex under normoxic and hypoxic conditions. The excitatory synaptic component of the evoked waveform was identified by its sensitivity to calcium and 6,7-dinitroquinoxaline-2,3-dione (DNQ...

The influence of neuronal activity on cortical axon branching was studied by imaging axons of layer 2/3 neurons in organotypic slice cultures of rat visual cortex. Upper layer neurons labeled by electroporation of plasmid encoding yellow fluorescent protein were observed by confocal microscopy. Time-lapse observation of single-labeled axons showed that axons started to branch after 8-10 d in vi...

Neurons of in vitro guinea pig and rat auditory cortex receive a complex synaptic pattern of afferent information. As many as four synaptic responses to a single-stimulus pulse to the gray or white matter can occur; an early-EPSP followed, sequentially, by an early-IPSP, late-EPSP, and late-IPSP. Paired pulse stimulation and pharmacological studies show that the early-IPSP can modify informatio...

INDEPENDENT EPILEPTIFORM DISCHARGE PATTERNS IN THE OLFACTORY AND LIMBIC AREAS OF THE IN 2 VITRO ISOLATED GUINEA PIG BRAIN DURING 4-AMINOPYRIDINE TREATMENT 3 4 Giovanni Carriero, Laura Uva, Vadym Gnatkovsky, Massimo Avoli and Marco de 5 Curtis 6 7 Unit of Experimental Neurophysiology and Epileptology, Fondazione Istituto Neurologico C. 8 Besta, via Celoria 11, 20133 Milano, Italy; Montreal Neuro...

The identity of the specific molecules required for the process of retinal circuitry formation is largely unknown. Here we report a newly identified zebrafish mutant in which the absence of the atypical cadherin, Celsr3, leads to a specific defect in the development of GABAergic signaling in the inner retina. This mutant lacks an optokinetic response (OKR), the ability to visually track rotatin...

GABAergic modulation of activity in avian cochlear nucleus neurons has been studied extensively in vitro. However, how this modulation actually influences processing in vivo is not known. We investigated responses of chicken nucleus magnocellularis (NM) neurons to sound while pharmacologically manipulating the inhibitory input from the superior olivary nucleus (SON). SON receives excitatory inp...

Interictal spikes in models of focal seizures and epilepsies are sustained by the synchronous activation of glutamatergic and GABAergic networks. The nature of population spikes associated with seizure initiation (pre-ictal spikes; PSs) is still undetermined. We analyzed the networks involved in the generation of both interictal and PSs in acute models of limbic cortex ictogenesis induced by ph...

The effects of cannabinoids on the baroreflex have been investigated in the nucleus tractus solitarii (NTS). In urethane-anesthetized rats, microinjection of the cannabinoid (CB) receptor agonist WIN 55212-2 (100 mM) into the NTS produced a short lasting decrease in arterial pressure (from 95.2 ± 2.9 to 76.2 ± 1.5, n=5, P<0.05) but no change in the heart rate. Another cannabinoid agonist, CP 55...

Accurate calculation of the binding affinity of small molecules to proteins has the potential to become an important tool in rational drug design. In this study, we use the free energy perturbation (FEP) method with restraints to calculate the standard binding free energy of five ligands (ACPA, AMPA, CNQX, DNQX, and glutamate) to the glutamate receptor GluA2, which plays an essential role in sy...

Estrogens exert protective effects against neurotoxic changes induced by over-activation of ionotrophic glutamate receptors, whereas little is known about their interaction with changes mediated by metabotropic glutamate receptors. We evaluated effects of estrone on quisqualate (QA)-induced toxicity in neuronal cell cultures on 7 and 12 day in vitro (DIV). Twenty four hour exposure to QA (150 m...