Author(s)

Toshiyuki Saito^1,2*, Sei-Etsu Fujiwara^2,3, Takashi Yamaguchi⁴

¹Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.
²National Institute of Agrobiological Sciences, Tsukuba, Japan.
³School of Medicine, St. Marianna University, Kawasaki, Japan.
⁴Graduate School of Science and Engineering, Yamagata University, Yonezawa, Japan.

We examined theta activity in the temporal hippocampus of ure-thane-chloralose-anesthetized pigs by stimulation with two chemical odors, beta-phenyl ethyl alcohol (PEA; rose-like odor) and n-amyl acetate (banana-like odor). Neural activity was recorded in the neural cell layer nearby fimbria of the temporal hippocampus in three of six animals. Odor stimulation with PEA at a low concentration (10^-4 w/w; 100 ppm) significantly increased power of the low-frequency theta band (type-2; 4 - 6 Hz) for the middle 10 s (w (3, 6, 2.5%) >2.56). The PEA odor at a higher concentration (10^-3 w/w; 1000 ppm), however, showed a tendency for gradual increase in the low-frequency theta but the response was insignificant compared with the control. On the other hand, odor stimulation with n-amyl acetate (10^-4 w/w; 100 ppm) caused no apparent increase or a tendency for decrease in power of the low-frequency theta. Thus, the type-2 theta response in the temporal hippocampus to the PEA odor contrasted strikingly with that to the n-amylacetate in the ure-thane-chloralose-anesthetized pigs. The response of the type-2 theta rhythm in the temporal hippocampus may underlie the difference in emotional sensation and cognition of PEA from n-amyl acetate in the pig.

Fast Fourier Transform, Rhythmic Oscillations, Sus scrofa domesticus

Saito, T. , Fujiwara, S. and Yamaguchi, T. (2017) Theta Activity in the Regio Inferior of the Temporal Hippocampus by Odor Stimulation in Anesthetized Pigs. Open Journal of Animal Sciences, 7, 365-375. doi: 10.4236/ojas.2017.74028.