Effects of parafascicular excitotoxic lesions on two-way active avoidance and odor-discrimination.
To investigate whether the parafascicular (PF) nucleus of the thalamus is involved in different learning and memory tasks, two experiments were carried out in adult male Wistar rats that were submitted to pre-training bilateral N-methyl-d-aspartate PF infusions (0.15M, pH 7.4; 1.2 microl/side, 0.2 microl/min). In Experiment 1, we evaluated the effects of PF lesions in two identical 30-trial training sessions, separated by a 24-h interval, of a two-way active avoidance conditioning. PF-lesioned rats exhibited impaired performance in both sessions, measured by number of avoidance responses. In Experiment 2, the effects of PF lesions were assessed in a training session (5 trials) and a 24-h retention test (2 retention trials and 2 relearning trials) of an odor-discrimination task. PF lesions did not significantly disrupt the acquisition or the first retention trial, which was not rewarded. However, lesioned animals' performance was clearly affected in subsequent trials, following the introduction of the single non-rewarded trial. Current data are discussed considering evidence that lesions of the PF nucleus affect learning and memory functions mediated by anatomically related areas of the frontal cortex and striatum.
Quiroz-Padilla
Maria Fernanda
MF
Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Institut de Neurociències, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
Guillazo-Blanch
Gemma
G
Vale-Martínez
Anna
A
Torras-García
Meritxell
M
Martí-Nicolovius
Margarita
M
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001362:Avoidance Learning / Q000502:physiology*; D020532:Basal Nucleus of Meynert / Q000166:cytology; D001522:Behavior, Animal / Q000502:physiology*; D003342:Corpus Striatum / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology; D007100:Imitative Behavior; D020646:Intralaminar Thalamic Nuclei / Q000166:cytology*; D008297:Male; D009812:Odorants; D051381:Rats; D017208:Rats, Wistar; D012153:Retention, Psychology / Q000502:physiology; D012931:Social Environment