Glutamatergic afferents from the hippocampus to the nucleus accumbens regulate activity of ventral tegmental area dopamine neurons.

@article{citeulike:973012, abstract = {Several studies have shown that the mesolimbic dopamine (DA) system is strongly influenced by the ventral subiculum (vSub) of the hippocampus. To examine whether this occurs by activation of DA neuron firing, the effects of chemical stimulation of the vSub on ventral tegmental area (VTA) DA neuron activity were examined using extracellular single-unit recordings. Infusions of NMDA into the vSub increased the number of spontaneously firing DA cells recorded per electrode track, while having no effect on firing rate or burst firing. This response was abolished by intranucleus accumbens (NAc) infusions of the glutamate receptor antagonist kynurenic acid. This effect did not involve the prefrontal cortex, because infusions of tetrodotoxin into the prefrontal cortex did not affect the increase in spontaneously active DA cells. Infusions of either kynurenic acid into the NAc or tetrodotoxin into the vSub decreased the firing rate and burst firing of DA neurons without altering the number of spontaneously active DA neurons. These data show that glutamatergic afferents from the vSub to the NAc exert a potent excitatory effect on VTA DA neurons, influencing both DA neuron population activity and the regulation of the firing properties of these neurons. As a result, dysfunctions in hippocampal circuitries may contribute to the hyperexcitable state of the DA system that is present in schizophrenia.}, address = {Departments of Neuroscience and Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. floresco@brain.bns.pitt.edu}, author = {Floresco, S. B. and Todd, C. L. and Grace, A. A. }, citeulike-article-id = {973012}, issn = {1529-2401}, journal = {J Neurosci}, keywords = {dopamine, hippocampus, nucleus-accumbens, ventral-subiculum, vta}, month = {July}, number = {13}, pages = {4915--4922}, posted-at = {2006-12-04 12:30:32}, priority = {0}, title = {Glutamatergic afferents from the hippocampus to the nucleus accumbens regulate activity of ventral tegmental area dopamine neurons.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11425919}, volume = {21}, year = {2001} }

TY - JOUR ID - citeulike:973012 L3 - citeulike-article-id:973012 TI - Glutamatergic afferents from the hippocampus to the nucleus accumbens regulate activity of ventral tegmental area dopamine neurons. JF - J Neurosci VL - 21 IS - 13 SP - 4915 EP - 4922 AD - Departments of Neuroscience and Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. floresco@brain.bns.pitt.edu SN - 1529-2401 N2 - Several studies have shown that the mesolimbic dopamine (DA) system is strongly influenced by the ventral subiculum (vSub) of the hippocampus. To examine whether this occurs by activation of DA neuron firing, the effects of chemical stimulation of the vSub on ventral tegmental area (VTA) DA neuron activity were examined using extracellular single-unit recordings. Infusions of NMDA into the vSub increased the number of spontaneously firing DA cells recorded per electrode track, while having no effect on firing rate or burst firing. This response was abolished by intranucleus accumbens (NAc) infusions of the glutamate receptor antagonist kynurenic acid. This effect did not involve the prefrontal cortex, because infusions of tetrodotoxin into the prefrontal cortex did not affect the increase in spontaneously active DA cells. Infusions of either kynurenic acid into the NAc or tetrodotoxin into the vSub decreased the firing rate and burst firing of DA neurons without altering the number of spontaneously active DA neurons. These data show that glutamatergic afferents from the vSub to the NAc exert a potent excitatory effect on VTA DA neurons, influencing both DA neuron population activity and the regulation of the firing properties of these neurons. As a result, dysfunctions in hippocampal circuitries may contribute to the hyperexcitable state of the DA system that is present in schizophrenia. KW - dopamine KW - hippocampus KW - nucleus-accumbens KW - ventral-subiculum KW - vta AU - Floresco, SB AU - Todd, CL AU - Grace, AA PY - 2001/07/01/ UR - http://view.ncbi.nlm.nih.gov/pubmed/11425919 ER -