Figure 3.

LTP-inducing stimulation of thalamo-LA synapses regulates Arc/Arg3.1 mRNA and protein in the lateral amygdala. a, Representative autoradiogram of a rat brain section depicting Arc/Arg3.1 mRNA expression after HFS of the auditory thalamus. The box depicts the location of the LA on the stimulated side of the brain. Higher level magnification of sections containing the ipsilateral LA from HFS and LFS rats are presented to the right. b, Quantification of Arc/Arg3.1 mRNA in the LA of HFS (n = 6) and LFS (n = 6) groups. The black bar represents the LA ipsilateral to the stimulation, whereas the gray bar represents the contralateral (nonstimulated) LA. *p < 0.05 relative to the contralateral side. c, Western blot analysis of Arc/Arg3.1 protein in the LA of HFS (n = 8) and LFS (n = 4) groups. The black bar represents the LA ipsilateral to the stimulation, whereas the gray bar represents the contralateral (nonstimulated) LA. *p < 0.05 relative to the contralateral side. Representative blots can be depicted in the inset. d, e, Representative 10× photomicrographs of immunolabeled Arc/Arg3.1 neurons in an HFS and LFS rat, respectively. f, g, Higher level (20 and 40×, respectively) magnifications of Arc/Arg3.1 labeled neurons from the box in the HFS rat in d. Note, as with fear conditioning, that Arc/Arg3.1 label is present throughout the soma, dendrites, and nucleus of LA cells.