Early weaning influences short-term synaptic plasticity in the medial prefrontal-anterior basolateral amygdala pathway.
Early weaning in rodents reportedly influences behavioral and emotional traits and triggers precocious myelin formation in the anterior basolateral amygdala (aBLA; Ono et al., 2008), where prefrontal efferents terminate. We studied the correlation between behavior and the synaptic properties of the prefrontal-aBLA pathway. Open-field behaviors of adult male rats weaned at either 16 days or 30 days were measured on two consecutive days. On the first day, the rats received a slight footshock that was reportedly insufficient for fear conditioning. Electrophysiological recordings in the prefrontal-aBLA were then performed under urethane anesthesia. Without group differences in the stimulus intensity or the first evoked response, the overall paired-pulse facilitation was significantly lower in the early-weaned group from 25 to 100 ms. At the 25-ms interval, regression values between paired-pulse facilitation and locomotion on the second day were positive/insignificant and negative/significant in early- and control-weaned groups, respectively, and were statistically different between the groups.
Brain Function Measurement Research Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan; Brain Science Inspired Life Support Research Center, The University of Electro-Communications, Tokyo, Japan. Electronic address: takita.m@aist.go.jp.
Masatoshi
M
Takita
Department of Animal Science and Biotechnology, Azabu University, Kanagawa, Japan.
Takefumi
T
Kikusui
D000818:Animals; D066276:Corticomedial Nuclear Complex / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D008124:Locomotion; D008297:Male; D009043:Motor Activity; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity; D017397:Prefrontal Cortex / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology; D014886:Weaning
Early weaning; Electric stimulation; Locomotion; Maternal environment; Open-field; Paired-pulse facilitation; Rearing