Through their actions in the nucleus accumbens (NAc), kappa opioid (KOP) receptors and their endogenous ligand, dynorphin, modify behaviors associated with the administration of drugs of abuse and are regulated by exposure to such drugs. Despite their demonstrated behavioral significance, the synaptic actions of KOP receptor ligands in the NAc are not clearly understood. Using whole-cell voltag...

Addictive behavior is increasingly accepted as a drug-associated pathological memory in which the hippocampus is profoundly engaged. It has been well documented that adaptations of synaptic plasticity of excitatory transmission in the hippocampus may contribute to opioid addiction. However, it remains unknown whether and how adaptive changes of synaptic plasticity of inhibitory transmission in ...

Synapses formed by the olfactory nerve (ON) provide the source of excitatory synaptic input onto mitral cells (MC) in the olfactory bulb. These synapses, which relay odor-specific inputs, are confined to the distally tufted single primary dendrites of MCs, the first stage of central olfactory processing. beta-adrenergic modulation of electrical and chemical signaling at these synapses may be in...

The deconvolution method has been used in the past to estimate release rates of synaptic vesicles, but it cannot be applied to synapses where nonlinear interactions of quanta occur. We have extended this method to take into account a nonlinear current component resulting from the delayed clearance of glutamate from the synaptic cleft. We applied it to the calyx of Held and verified the importan...

CA1 pyramidal cells receive two major excitatory inputs; the perforant path (PP) terminates in the most distal dendrites whereas the Schaffer collateral (SC) terminates more proximally. We have examined the mechanism of the afterhyperpolarization (AHP) that follows single subthreshold EPSPs in these inputs. The AHPs were not reduced by a GABA A antagonist or by agents that block Ca 2+ entry. Ap...

In the present study, manganese (Mn), a neuromuscular blocker with pre and postsynaptic actions, was used to verify the neurotoxicity and myotoxicity induced by Crotalus durissus terrificus (Cdt) and Bothrops jararacussu (Bjssu) venoms in biventer cervicis preparations (BCp). Preparations pretreated with 0.66 and 1.6mM Mn did not affect Cdt venom-induced blockage nor change KCl-induced contract...

Synapses formed by the olfactory nerve (ON) provide the source of excitatory synaptic input onto mitral cells (MC) in the olfactory bulb. These synapses, which relay odor-specific inputs, are confined to the distally tufted single primary dendrites of MCs, the first stage of central olfactory processing. -adrenergic modulation of electrical and chemical signaling at these synapses may be involv...

Because inhibitory synaptic transmission is a major mechanism of general anesthesia, we examined the effects of isoflurane on properties of GABAergic inhibitory currents in the reticular thalamic nucleus (nRT) in brain slices. The evoked IPSCs (eIPSCs) and spontaneous miniature synaptic currents (mIPSCs) of visualized nRT cells in young and adult rats were recorded. Consistent with postsynaptic...

Homeostatic plasticity is thought to be important in preventing neuronal circuits from becoming hyper- or hypoactive. However, there is little information concerning homeostatic mechanisms following in vivo manipulations of activity levels. We investigated synaptic scaling and intrinsic plasticity in CA1 pyramidal cells following 2 days of activity-blockade in vivo in adult (postnatal day 30; P...

25 The voltage-gated potassium channel, Kv1.3 has been reported to regulate transmitter 26 release in select central and peripheral neurons. In this study we evaluated its role at 27 the synapse between visceral sensory afferents and secondary neurons in the nucleus 28 of the solitary tract (nTS). We identified mRNA and protein for Kv1.3 in rat nodose 29 ganglia (NG) using RT-PCR and Western bl...