The close anatomical relationship between the septal nuclei and the hippocampus within the limbic system is well known. Much recent research, at the cellular level, has been concerned with the physiology and pharmacology of neurons within the hippocampus, but little comparable data is available about neurons in the septal nuclei. We have developed an in vitro brain slice preparation to record intracellularly from individual rat dorsolateral and medial septal neurons. Our goal is to characterize individual septal neurons on an electrophysiological, pharmacological and anatomical bases so that we can determine which specific neurons in these nuclei serve a """"""""pacemaker"""""""" function and how these neurons generate an electrical activity termed theta rhythm. Theta rhythm can be recorded from various parts of the limbic system, but its focus of origin is currently thought to reside either in the septum or the hippocampus. We will proceed on the hypothesis that theta rhythm is generated in the septum and determine how this rhythm is affected by endogenously released neurotransmitters such as: norepinephrine, dopamine, serotonin, acetylcholine or excitatory and inhibitory amino acids. We will compare responses induced by exogenous, iontophoretic application of these same substances on septal neurons. Finally, we will examine how benzodiazepines, the most often prescribed behaviorally active drugs, affect both spontaneous and evoked electrical activity. We believe information obtained from this proposal will have broad basic and clinical science applications, since modification of septal neuron activity has been implicated in both normal and abnormal cognitive processes such as learning and memory, and in normal and abnormal expressions of our emotions. Specific mental disorders that may benefit from the results of this proposal include: schizophrenia, depression, mania, epilepsy, senile dementia, and Alzheimer's Disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
1R01MH039163-01A1
Application #
3377138
Study Section
(BPNA)
Project Start
1985-04-15
Project End
1988-03-31
Budget Start
1985-04-15
Budget End
1986-03-31
Support Year
1
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Type
Schools of Medicine
DUNS #
041367053
City
Galveston
State
TX
Country
United States
Zip Code
77555
Hasuo, H; Akasu, T; Gallagher, J P (1996) Muscarine activates a nonselective cation current through a M3 muscarinic receptor subtype in rat dorsolateral septal nucleus neurons. J Neurophysiol 76:2221-30
Zheng, F; Gallagher, J P; Connor, J A (1996) Activation of a metabotropic excitatory amino acid receptor potentiates spike-driven calcium increases in neurons of the dorsolateral septum. J Neurosci 16:6079-88
Phelan, K D; Sacaan, A; Gallagher, J P (1996) Retrograde labeling of rat dorsolateral septal nucleus neurons following intraseptal injections of WGA-HRP. Synapse 22:261-8
Zheng, F; Hasuo, H; Gallagher, J P (1995) 1S,3R-ACPD-preferring inward current in rat dorsolateral septal neurons is mediated by a novel excitatory amino acid receptor. Neuropharmacology 34:905-17
Zheng, F; Gallagher, J P (1995) Pharmacologically distinct, pertussis toxin-resistant inward currents evoked by metabotropic glutamate receptor (mGluR) agonists in dorsolateral septal nucleus (DLSN) neurons. J Neurosci 15:504-10
Zheng, F; Gallagher, J P (1995) (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid-induced burst firing is mediated by a native pertussis toxin-sensitive metabotropic receptor at rat dorsolateral septal nucleus neurons. Neuroscience 68:423-34
Gallagher, J P; Zheng, F; Hasuo, H et al. (1995) Activities of neurons within the rat dorsolateral septal nucleus (DLSN). Prog Neurobiol 45:373-95
Zheng, F; Lonart, G; Johnson, K M et al. (1994) (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) induces burst firing via an inositol-1,4,5-triphosphate-independent pathway at rat dorsolateral septal nucleus. Neuropharmacology 33:97-102
Phelan, K D; Twery, M J; Gallagher, J P (1993) Morphological and electrophysiological evidence for electrotonic coupling of rat dorsolateral septal nucleus neurons in vitro. Synapse 13:39-49
Zheng, F; Gallagher, J P (1992) Metabotropic glutamate receptor agonists potentiate a slow afterdepolarization in CNS neurons. Neuroreport 3:622-4

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