Recent in vitro experiments revealed that the GABAA reversal potential is about 10 mV higher than the resting potential in mature mammalian neocortical pyramidal cells; thus GABAergic inputs could have facilitatory, rather than inhibitory, effects on action potential generation under certain conditions. However, how the relationship between excitatory input conductances and the output firing ra...

Homeostatic plasticity ensures that appropriate levels of activity are maintained through compensatory adjustments in synaptic strength and cellular excitability. For instance, excitatory glutamatergic synapses are strengthened following activity blockade and weakened following increases in spiking activity. This form of plasticity has been described in a wide array of networks at several diffe...

The ability of synaptically released GABA to facilitate action potential generation in striatal projection neurons was studied in brain slices using current-clamp, gramicidin-perforated whole cell recordings. Evoked GABAergic postsynaptic potentials (PSPs) were pharmacologically isolated with ionotropic glutamate receptor antagonists. Subthreshold depolarizing current injections were paired wit...

Introduction: We previously shown that microinjection of glutamate into the hDB of rat elicited cardiovascular depressive responses. Microinjection of AP5 (an NMDA receptor antagonist, 2.5 mM, 50 nl) and CNQX (an AMPA receptor antagonist, 1 mM, 50 nl) caused no significant changes in the blood pressure and heart rate. Microinjection of bicuculline (BMI: a GABAA receptor antagonist, 1 mM, 50...

Immunocytochemical studies were carried out on the morphological relation between primary afferent central terminals (C-terminals) and GABAergic neurons in the mouse superficial dorsal horn. The superficial dorsal horn is composed of many synaptic glomeruli comprising two types: Type I with centrally located CI-terminals surrounded by several dendrites and few axonal endings, and Type II with c...

The transmitter release from GABAergic synapses is thought to be calcium (Ca2+) dependent. The pharmacological modulation of Ca2+ currents in central GABAergic neurons may strongly affect GABA release from synaptic sites. The source of striatal GABA-containing synapses is intrinsic to the striatum and mainly originates from axon collaterals of projecting medium-spiny neurons. In order to charac...

Sodium salicylate (NaSal), a tinnitus inducing agent, can activate serotonergic (5-HTergic) neurons in the dorsal raphe nucleus (DRN) and can increase serotonin (5-HT) level in the inferior colliculus and the auditory cortex in rodents. To explore the underlying neural mechanisms, we first examined effects of NaSal on neuronal intrinsic properties and the inhibitory synaptic transmissions in DR...

In rat hippocampal cultures, we show by multilabeling immunocytochemistry that pyramidal cells, which receive little or no GABAergic input, mistarget alpha2-GABA(A) receptors and gephyrin to glutamatergic terminals. This mismatch does not occur in neurons innervated by numerous GABAergic terminals. A similar phenomenon has been reported for isolated autaptic hippocampal neurons (Rao et al., 200...

The superficial superior colliculus (sSC) is a key station in the sensory processing related to visual salience. The sSC receives cholinergic projections from the parabigeminal nucleus, and previous studies have revealed the presence of several different nicotinic acetylcholine receptor (nAChR) subunits in the sSC. In this study, to clarify the role of the cholinergic inputs to the sSC, we exam...