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Pentylenetetrazole (PTZ)-induced c-fos expression in the hippocampus of kindled rats is suppressed by concomitant treatment with naloxone.
Brain Res. 1998 May 11; 792(2):299-308.BR

Abstract

Rats were kindled by repeated injections of pentylenetetrazole (PTZ; 37.5 mg/kg; i.p.) in the presence or absence of the opioid receptor antagonist naloxone. Naloxone (10 mg/kg; i.p.) applied 30 min before each PTZ application had no major effect on the seizure development, although a slight decrease in the seizure expression of fully kindled animals could be observed. In the kindled animals, a pronounced but transient increase in c-fos mRNA level was observed in several brain areas after the injection of PTZ. The magnitude of c-fos induction was related to the seizure stage reached. Detectable c-fos mRNA levels in the cortex were observed in rats showing stage four seizures, whereas the expression of c-fos in the hippocampus required stage five kindled seizures. The induction of c-fos expression in the hippocampus of stage five kindled rats but not in other brain areas was prevented by treatment of naloxone prior to each PTZ application. In contrast, a single injection of naloxone to kindled rats was not sufficient to prevent c-fos mRNA expression in the hippocampus. In addition, a single PTZ application (at the higher dose of 45 mg/kg) to rats that were not kindled also caused c-fos expression in several brain regions, but this was not influenced by naloxone. Assuming that c-fos expression reflects neuronal activity our findings suggest a functional role of endogenous opioid peptides in the development of kindling-induced neuronal excitation in the hippocampus. In addition, the excitation of the hippocampus does not appear to be involved in the seizure activity but may be responsible for the impairment of learning in PTZ-kindled rats which can be prevented by pretreatment with naloxone [A. Becker, G. Grecksch, M. Brosz, Naloxone ameliorates the learning deficit induced by pentylenetetrazole kindling in rats, Eur. J. Neurosci. 6 (1994) 1512-1515].

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Authors+Show Affiliations

Erdtmann-Vourliotis M
Institute for Pharmacology and Toxicology, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
Riechert U
No affiliation info available
Mayer P
No affiliation info available
Grecksch G
No affiliation info available
Höllt V
No affiliation info available

MeSH

AmygdalaAnimalsConvulsantsDentate GyrusEpilepsyGene ExpressionGyrus CinguliIn Situ HybridizationKindling, NeurologicMaleNaloxoneNarcotic AntagonistsOpioid PeptidesPentylenetetrazoleProto-Oncogene Proteins c-fosRNA, MessengerRatsRats, WistarReceptors, OpioidSeptal Nuclei

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9593956

Citation

Erdtmann-Vourliotis, M, et al. "Pentylenetetrazole (PTZ)-induced C-fos Expression in the Hippocampus of Kindled Rats Is Suppressed By Concomitant Treatment With Naloxone." Brain Research, vol. 792, no. 2, 1998, pp. 299-308.
Erdtmann-Vourliotis M, Riechert U, Mayer P, et al. Pentylenetetrazole (PTZ)-induced c-fos expression in the hippocampus of kindled rats is suppressed by concomitant treatment with naloxone. Brain Res. 1998;792(2):299-308.
Erdtmann-Vourliotis, M., Riechert, U., Mayer, P., Grecksch, G., & Höllt, V. (1998). Pentylenetetrazole (PTZ)-induced c-fos expression in the hippocampus of kindled rats is suppressed by concomitant treatment with naloxone. Brain Research, 792(2), 299-308.
Erdtmann-Vourliotis M, et al. Pentylenetetrazole (PTZ)-induced C-fos Expression in the Hippocampus of Kindled Rats Is Suppressed By Concomitant Treatment With Naloxone. Brain Res. 1998 May 11;792(2):299-308. PubMed PMID: 9593956.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Pentylenetetrazole (PTZ)-induced c-fos expression in the hippocampus of kindled rats is suppressed by concomitant treatment with naloxone. AU - Erdtmann-Vourliotis,M, AU - Riechert,U, AU - Mayer,P, AU - Grecksch,G, AU - Höllt,V, PY - 1998/6/24/pubmed PY - 1998/6/24/medline PY - 1998/6/24/entrez SP - 299 EP - 308 JF - Brain research JO - Brain Res VL - 792 IS - 2 N2 - Rats were kindled by repeated injections of pentylenetetrazole (PTZ; 37.5 mg/kg; i.p.) in the presence or absence of the opioid receptor antagonist naloxone. Naloxone (10 mg/kg; i.p.) applied 30 min before each PTZ application had no major effect on the seizure development, although a slight decrease in the seizure expression of fully kindled animals could be observed. In the kindled animals, a pronounced but transient increase in c-fos mRNA level was observed in several brain areas after the injection of PTZ. The magnitude of c-fos induction was related to the seizure stage reached. Detectable c-fos mRNA levels in the cortex were observed in rats showing stage four seizures, whereas the expression of c-fos in the hippocampus required stage five kindled seizures. The induction of c-fos expression in the hippocampus of stage five kindled rats but not in other brain areas was prevented by treatment of naloxone prior to each PTZ application. In contrast, a single injection of naloxone to kindled rats was not sufficient to prevent c-fos mRNA expression in the hippocampus. In addition, a single PTZ application (at the higher dose of 45 mg/kg) to rats that were not kindled also caused c-fos expression in several brain regions, but this was not influenced by naloxone. Assuming that c-fos expression reflects neuronal activity our findings suggest a functional role of endogenous opioid peptides in the development of kindling-induced neuronal excitation in the hippocampus. In addition, the excitation of the hippocampus does not appear to be involved in the seizure activity but may be responsible for the impairment of learning in PTZ-kindled rats which can be prevented by pretreatment with naloxone [A. Becker, G. Grecksch, M. Brosz, Naloxone ameliorates the learning deficit induced by pentylenetetrazole kindling in rats, Eur. J. Neurosci. 6 (1994) 1512-1515]. SN - 0006-8993 UR - https://www.unboundmedicine.com/medline/citation/9593956/Pentylenetetrazole__PTZ__induced_c_fos_expression_in_the_hippocampus_of_kindled_rats_is_suppressed_by_concomitant_treatment_with_naloxone_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-8993(98)00159-0 DB - PRIME DP - Unbound Medicine ER -