Deletion of miR212/132 influences hippocampal synaptic transmission and plasticity.

<p>A) Plot of fEPSP slope vs stimulus strength (mean ± SEM) showing that basal synaptic transmission is reduced by ∼30% in miR 212/132 KO slices (grey circles) compared to control (fl/fl) slices (black circles). Inset are representative fEPSPs at each of the stimulus strengths for fl/fl (left, black traces) and KO (right, grey traces) slices. Scale bar measures 5 ms and 1 mV. B) Paired-pulse facilitation (mean ± SEM) is no different between control (black circles) and miR KO slices (grey circles). Inset are representative fEPSPs at each of the inter-pulse intervals for control (left, black traces) and KO (right, grey traces) slices. Scale bar measures 100 ms and 1 mV. A and B represent data from 17 slices from 8 KO, and 11 slices from 6 control mice. C) LTP induced by tetanic stimulation (100 Hz for 1s) was not appreciably different between fl/fl (black circles) and KO mice (grey circles). Inset are fEPSPs taken before (smaller of the traces) and 60 mins after the induction of LTP (larger of the two traces) in fl/fl (left, black traces) and KO (right, grey traces) slices. Data from 11 slices from 8 KO mice and 6 slices from 4 control mice. Mean ± SEM. Scale bar measures 5 ms and 1 mV. D) In contrast, theta-burst stimulation (5 episodes at 10 s intervals of theta-burst stimulation (5 pulses at 100 Hz, repeated 10 times with 200 ms interval)) revealed greater LTP in KO slices (grey circles) compared to fl/fl (black circles) slices (p<0.05 at 55–65^th minute; unpaired t-test). Inset are fEPSPs taken before (smaller of the traces) and 60 mins after the induction of LTP (larger of the two traces) in fl/fl (left, black traces) and KO (right, grey traces) slices. The black and grey triangles hovering at 100% refer to the slope of fEPSPs from a simultaneously recorded control pathway for fl/fl and KO slices, respectively. Data from 13 slices from 5 KO mice and 6 slices from 2 fl/fl mice. Scale bar measures 5 ms and 1 mV. Data is presented as mean ± SD.