In Situ Microvoltammetry of Alveus from Resected Temporal Lobe in Patients with Mesial (MTLE) and Neocortical (NTLE) Temporal Lobe Epilepsy.
Abstract number :
3.204
Submission category :
Year :
2001
Submission ID :
1677
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
S.V. Pacia, M.D., Comprehensive Epilepsy Center, NYU Medical School, New York, NY; W.K. Doyle, M.D., Neurosurgery, NYU School of Medicine, New York, NY; P.A. Broderick, Ph.D., Physiology, Pharmacology and Neurology, CUNY and NYU Medical Schools, New York,
RATIONALE: We previously reported significant differences in monoamine signatures from hippocampal subparcellations in patients with MTLE and NTLE. The alveus contains both efferent fibers from hippocampus which form the fornix and afferent pathways connecting entorhinal cortex and the CA1 region of the hippocampus. We studied the neurochemistry of the alveus in patients with MTLE and NTLE to determine whether similar neurotransmitter alterations exist.
METHODS: We used microvoltammetry with Broderick Probe[reg] stearic acid microelectrodes to detect norepinephrine (NE), dopamine (DA), and serotonin (5-HT) in resected temporal lobes of 9 MTLE and 4 NTLE patients with temporal lobe epilepsy. Neurotransmitters were detected in separate signals within the same recording within seconds in alveus, by experimentally derived oxidative potentials, determined in vitro in Ringers Lactate or PO4 Buffer. Ag/AgCl reference and stainless steel auxiliary microelectrodes were placed in each specimen 4-6 mm from indicator microelectrodes (patented) (manufactured on site). Methods are published (Broderick, Neurosci. Lett. 95, 1988; Br. Res. 495, 1989; Broderick et al. Br. Res. 878, 2000; Pacia et al. Br. Res. 899, 2001).
RESULTS: All of the NTLE patients had significant DA in the alveus while only one MTLE patient had detectable DA (p[lt]0.01, Mann- Whitney Rank Sum Test). Eight of the nine MTLE patients had significant NE in alveus while none of the NTLE patients exhibited NE (p[lt]0.01, Mann- Whitney Rank Sum Test). Both MTLE and NTLE patients had 5-HT but 5-HT concentrations were significantly higher in NTLE specimens (p[lt]0.01, Mann- Whitney Rank Sum Test).
CONCLUSIONS: The neurochemical profiles in alveus of patients with MTLE and NTLE reveal similar neurotransmitter alterations to the hippocampal pyramidal cell layer of these patients, a region with direct afferent and efferent connections through the alveus.
Support: Parents Against Childhood Epilepsy (PACE)