Detailed information regarding the contribution of individual gamma-aminobutyric acid (GABA)-containing inhibitory neurons to the overall synaptic activity of single postsynaptic cells is essential to our understanding of fundamental elements of synaptic integration and operation of neuronal circuits. For example, GABA-containing cells in the thalamic reticular nucleus (nRt) provide major inhib...

Recent experimental and modeling results demonstrated that surviving mossy cells in the dentate gyrus play key roles in the generation of network hyperexcitability. Here we examined if mossy cells exhibit long-term plasticity in the posttraumatic, hyperexcitable dentate gyrus. Mossy cells 1 wk after fluid percussion head injury did not show alterations in their current-firing frequency (I-F) an...

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...

Brain functions are based on the dynamic interaction of excitatory and inhibitory inputs. Spillover of glutamate from excitatory synapses may diffuse to and modulate nearby inhibitory synapses. By recording unitary inhibitory postsynaptic currents (uIPSCs) from cell pairs in CA1 of the hippocampus, we demonstrated that low concentrations of Kainate receptor (KAR) agonists increased the success ...

The pathway from cortical layer 6 to the thalamus is a property of all thalamic relay nuclei. This pathway, as a population, directly excites relay cells and indirectly inhibits them via the thalamic reticular nucleus. To understand the circuit organization of this cortical feedback, we used laser-scanning photostimulation, which specifically activates somata or dendrites, to stimulate the prim...

Neurons in the dorsal motor nucleus of the vagus (DMV) play a critical role in the regulation of autonomic functions. Previous studies indicated that central activation of sirtuin 1 (SIRT1) has beneficial effects on homeostasis, most likely via modulation of the autonomic output. Sirtuins are NAD(+)-dependent deacetylases and have been associated with longevity. SIRT1 is one of the best-charact...

Using whole cell patch-clamp recording in a rat brain stem slice preparation, we found that gamma-aminobutyric acid (GABA) and glycine act as cotransmitters to hypoglossal motoneurons (HMs). Focal application of GABA and glycine onto a single HM revealed that GABAA and glycine receptors are present on the same neuron. To demonstrate that HMs receive both GABAergic and glycinergic synaptic input...

The nature of synaptic interactions between cells is either excitatory or inhibitory. Activity in one cell either enhances or reduces activity in the target neuron. The strength of this influence and its duration are quite variable among synapses, and the mechanisms responsible for the postsynaptic effect are also variable. The classic syn-aptic action is to open ion channels, causing excitator...

The airway vagal preganglionic neurons (AVPNs) in the external formation of the nucleus ambiguus (eNA) play a major role in the vagal control of tracheobronchial smooth muscle tone and maintenance of airway resistance. The eNA receives vasopressinergic projection from the hypothalamic paraventricular nucleus (PVN), the key node for the genesis of psychological stress. Since airway vagal excitat...

The hypocretin/orexin arousal system plays a key role in maintaining an alert wake state. The hypocretin peptide is colocalized with an opioid peptide, dynorphin. As dynorphin may be coreleased with hypocretin, we asked what action simultaneous stimulation with the excitatory neuropeptide hypocretin and the inhibitory peptide dynorphin might exert on cells postsynaptic to hypocretin axons, incl...