Previous studies have suggested that photoreceptor synaptic inputs to depolarizing bipolar cells (DBCs or ON bipolar cells) are mediated by mGluR6 receptors and those to hyperpolarizing bipolar cells (HBCs or OFF bipolar cells) are mediated by AMPA/kainate receptors. Here we show that in addition to mGluR6 receptors which mediate the sign-inverting, depolarizing light responses, subpopulations ...

We studied the responses of isolated and intact luminosity-type horizontal cells (L-HC) in the Xenopus retina to L-glutamate (L-glu) and its analogs. Isolated L-HCs studied with whole-cell patch clamp responded to L-glu, kainate (KA), AMPA, or quisqualate (quis) with inward currents from a holding potential of -60 mV, associated with a conductance increase. The current elicited by KA was relati...

A particular characteristic of the neonatal hippocampus is the presence of spontaneous network-driven oscillatory events, the so-called giant depolarizing potentials (GDPs). GDPs depend on the interplay between GABA and glutamate. Early in development, GABA, acting on GABAA receptors, depolarizes neuronal membranes via a Cl- efflux. Glutamate, via AMPA receptors, generates a positive feedback n...

The nucleus accumbens shell (AcbSh) and lateral hypothalamus (LH) are linked in the control of food intake. Pharmacological inhibition of the LH may block AcbSh-elicited feeding, but the behavioral phenotype associated with this feeding suppression is unknown. To examine this phenotype, adult male Sprague-Dawley rats were implanted with three cannulas - one unilaterally in the AcbSh and two bil...

Five minutes of oxygen and glucose deprivation (termed "in vitro ischemia") causes long-term synaptic transmission failure (LTF) in the CA1 region of the rat hippocampal slice. Dependence of LTF on cell calcium was tested by generating graded reductions in cell Ca. There was a strong correlation between the average level of exchangeable cell Ca in CA1 during ischemia, and the extent of LTF. In ...

Nicotinic acetylcholine receptors (nAChRs) can modulate transmitter release. Striatal [(3)H]dopamine ([(3)H]DA) release is regulated by presynaptic nAChR on dopaminergic terminals and alpha7 nAChR on neighboring glutamatergic afferents. Here, we explored the role of alpha7 nAChR in the modulation of [(3)H]noradrenaline ([(3)H]NA) release from rat hippocampal slices. The nicotinic agonist anatox...

GABA receptor regulation of NMDA-receptor-mediated synaptic responses was studied in area CA1 of the rat hippocampus using extracellular and intracellular recording techniques. Picrotoxin (PTX) was used to suppress GABAA inhibition and 6,7-dinitroquinoxaline-2,3-dione (DNQX) was used to suppress non-NMDA receptor-mediated responses. In this manner, we were able to avoid the complicating factors...

Brainstem 5-hydroxytryptamine (5-HT, serotonin)-containing neurones modulate cardiovascular reflex responses but the differing roles of the many 5-HT receptors have not been thoroughly investigated. The present experiments on anaesthetized rats investigated the role of 5-HT3 receptors in modulating vagal afferent evoked activity of nucleus tractus solitarius (NTS) neurones. Recordings were made...

Although the synaptic physiology of the amygdala has been studied with single neuron recordings, the properties of the networks between the various nuclei have resisted characterization because of the limitations of field recording in a neuronally diffuse structure. We addressed this issue in the rat amygdala complex in vitro by using a photodiode array coupled with a voltage-sensitive dye. Low...

The synaptic pharmacology of the lateral superior olive (LSO) and medial nucleus of the trapezoid body (MNTB) was examined in a brain slice preparation of the mouse superior olivary complex (SOC). Physiological responses in SOC were elicited by electrical stimulation of the trapezoid body ipsilateral or contralateral to the recording site, and bilateral interactions were investigated by combine...