Intracerebral Administration of Penicillin Modifies Benzodiazepine Receptor Binding in Rat Amygdala Nucleus.
Abstract number :
2.091
Submission category :
Year :
2001
Submission ID :
218
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
L. Carmona-Aparicio, QFB, Farmacobiologia, CINVESTAV-IPN, Mexico, DF, Mexico; A. Martinez-Cervantes, Biol., Neurociencias, Instituto Nacional de Psiquiatria, Mexico, DF, Mexico; M. Briones, Neurociencias, Instituto Nacional de Psiquiatria, Mexico, DF, Mex
RATIONALE: Human temporal lobe epilepsy (TLE) is characterized by a decreased benzodiazepine (BDZ) receptor binding in hippoccampus and amygdala. At present there is not experimental model that parallels these alterations. BDZ receptor binding changes were evaluated following the repetitive administration of penicillin into amygdala nucleus.
METHODS: Adult male Wistar rats were used as follows: the penicillin-treated rats (n=7) received daily administration of penicillin G (50 UI in 1 ul of saline sol.) into right basolateral amygdala nucleus; controls (n=7) were manipulated as previously described, except that they received a saline sol. injection (1 ul). Electrographic recordings were obtained 5 min before and during 15 min after each injection. Animals were sacrificed 24 h after the last administration and the brain was used for in vitro autoradiography experiments. BDZ receptor binding was evaluated in frontal, cingulate, sensorimotor and piriform cortices; caudate putamen, thalamus, hippocampus and amygdala nuclei, ipsilateral and contralateral to the place of injection.
RESULTS: When compared with the control group, the penicillin group showed decreased BDZ receptor binding in right basolateral and left medial amygdala nuclei (-73% and -22%, respectively). Although hippocampus, sensorimotor and piriform cortices presented reduced BDZ levels, values were not statistically significant.
CONCLUSIONS: The penicillin-induced BDZ receptor binding changes resemble the BDZ binding alterations observed in patients with TLE. These findings suggest that penicillin-induced seizures could be a good experimental model of TLE.
Support: CONACyT (31702M grant and 153280 scholarship).