Effect of hippocampal and neocortical spreading depression on rat shuttle behavior in four different experimental paradigms.

摘要: Abstract As shown in previous papers, rat shuttle responses to a buzzer (SBs) depend on the operation of three main factors: state drive (D) determined by presence footshocks experimental situation; pairing (i.e., fixed temporal relation) buzzers and shocks (P); contingency (C) upon SBs. Four tests were studied which these factors operate various combinations: (a) D test: 50 25 at random intervals sequence; (b) DP test (Pavlovian conditioning): paired (contiguous) trials, regardless whether SBs are performed or not; (c) DC buzzers, each followed shock randomly variable interval unless there is an SB that trial; (d) DPC (two-way avoidance): only those trials no SB. The effect hippocampal neocortical spreading depression was studied. Spreading induced application KCl crystals through implanted guide cannulae, ascertained EEG recording. Application hippocampus caused both depression; whereas when it applied neocortex this structure. following behavioral measured: SBs, jumping buzzer, intertial shuttling. Neocortical had any parameters. Hippocampal increase intertrial crossings all four tests, test. more marked tests. In fact, animals with differences performance between D, DC, very small not significant; case other groups. Since, as previously - measure P factor, data suggest normally exerts tonic inhibitory influence same time plays role P. results consistent hypotheses attribute hippocampusa inhibition, consider processes stimulus-stimulus dependent information.