Pentylenetetrazole as an unconditioned stimulus for olfactory and contextual fear conditioning in rats.
The association of five footshocks with a neutral odor is able to establish an olfactory fear conditioning in rats. The present study sought to investigate whether the systemic administration of pentylenetetrazole (PTZ; 3.75-15 mg/kg) would turn the coffee odor in a conditioned stimulus in the fear conditioning paradigm. The results showed that rats started to display risk assessment and avoidance after PTZ (15 mg/kg)-coffee odor pairing. When three mild footshocks (0.4 mA for 2 s) were delivered during this pairing, the conditioned response exhibited was greater than before. In both cases, however, pretreatment with the benzodiazepine midazolam (MDZ. 0.5 mg/kg i.p.) fully counteracted the expression of these defensive behaviors. Moreover, after being paired with 15 mg/kg of PTZ alone or combined with footshocks, the coffee odor was able to promote a new fear conditioning related to the context where it was re-exposed. The present findings point out the usefulness of PTZ as an unconditioned stimulus to promote fear conditioning to olfactory and contextual cues in rats.
Cavalli
Juliana
J
Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil.
Bertoglio
Leandro J
LJ
Carobrez
Antonio P
AP
D000818:Animals; D001007:Anxiety / Q000139:chemically induced* / Q000523:psychology; D001245:Association Learning / Q000187:drug effects*; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D003214:Conditioning, Classical / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects* / Q000502:physiology; D004597:Electroshock; D004777:Environment; D005239:Fear / Q000187:drug effects / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology*; D018757:GABA Modulators / Q000494:pharmacology; D008297:Male; D008874:Midazolam / Q000494:pharmacology; D009812:Odorants; D055696:Olfactory Perception; D010433:Pentylenetetrazole / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D018756:GABA Antagonists; D018757:GABA Modulators; D008874:Midazolam; D010433:Pentylenetetrazole