Chronic phencyclidine treatment induces long-lasting glutamatergic activation of VTA dopamine neurons.

Use of phencyclidine (PCP) can mimic some aspects of schizophrenia. However, the underlying mechanism is unclear. Administration of PCP is known to activate mesolimbic dopamine pathway.

Leptin facilitates learning and memory performance and enhances hippocampal CA1 long-term potentiation and CaMK II phosphorylation in rats.

Leptin, an adipocytokine encoded by an obesity gene and expressed in adipose tissue, affects feeding behavior, thermogenesis, and neuroendocrine status via leptin receptors distributed in the brain, especially in the hypothalamus. Leptin may also modulate the synaptic plasticity and behavioral performance related to learning and memory since: leptin receptors are found in the hippocampus, and both leptin and its receptor share structural and functional similarities with the interleukin-6 family of cytokines that modulate long-term potentiation (LTP) in the hippocampus. We therefore examined the effect of leptin on (1) behavioral performance in emotional and spatial learning tasks, (2) LTP at Schaffer collateral-CA1 synapses, (3) presynaptic and postsynaptic activities in hippocampal CA1 neurons, (4) the intracellular Ca(2+) concentration ([Ca(2+)](i)) in CA1 neurons, and (5) the activity of Ca(2+)/calmodulin protein kinase II (CaMK II) in the hippocampal CA1 tissue that exhibits LTP.

Gamma aminobutyric acid regulates glucosensitive neuropeptide Y neurons in arcuate nucleus via A/B receptors.

Gamma aminobutyric acid (GABA) is localized in neuropeptide Y (NPY) neurons of the hypothalamic arcuate nucleus (ARC). We examined regulation of ARC NPY neurons by GABA. Light and electron microscopic immunohistochemistry confirmed that GABA-containing nerve terminals contacted NPY-containing neurons in the ARC.

Orexins (hypocretins) directly interact with neuropeptide Y, POMC and glucose-responsive neurons to regulate Ca 2+ signaling in a reciprocal manner to leptin: orexigenic neuronal pathways in the mediobasal hypothalamus.

Orexin-A and -B (hypocretin-1 and -2) have been implicated in the stimulation of feeding. Here we show the effector neurons and signaling mechanisms for the orexigenic action of orexins in rats. Immunohistochemical methods showed that orexin axon terminals contact with neuropeptide Y (NPY)- and proopiomelanocortin (POMC)-positive neurons in the arcuate nucleus (ARC) of the rats.

[Regulation of psychomotor functions by dopamine: integration of various approaches].

(1)The basal ganglia circuitry mediates a wide rage of brain functions such as motor control, behavioral planning, and reward prediction. Dopamine (DA) transmission plays an essential role in the regulation of these brain functions. DA action not only regulates the firing activity of target neurons but also is involved in the pattern formation of their firing.