Effects of Lesions of Hippocampal Fields CA1 and CA3 on Acquisition of Inhibitory Avoidance

Abstract

Performance decrements of inhibitory avoidance (IA) induced by lesions in either the dorsal or ventral hippocampus have been interpreted as a deficiency in acquisition. Alternative interpretations are that short-term learning occurs despite the lesions and the long-term performance decrements reflect a failure of consolidation or retrieval. To assess the alternative explanations of the performance decrements, rats received lesions in either CA1 or CA3 fields of dorsal and ventral hippocampus, respectively, 8 days before IA training. Retention was tested at 30 min or 24 h after training. Kainic acid lesions were also produced in either hippocampal field 1 day after training and retention measured 8 days later. The group assessed 30 min after IA training showed little or no performance decrements, whereas the remaining groups did show marked performance decrements. These results do not support the conclusion that the hippocampus is essential for acquisition and support the idea that the hippocampus is highly involved in the consolidation or retrieval of information germane to these procedures.

Intense emotional experiences and enhanced training prevent memory loss induced by post-training amnesic treatments administered to the striatum, amygdala, hippocampus or substantia nigra

“…We found that excitotoxic lesions of CA1 and CA2 hippocampal fields disrupted long-term memory (Mart í nez et al, 2002), an effect similar to those of other treatments (Izquierdo et al, 1992;Lorenzini et al, 1996;Stubley-Wheatherly et al, 1996). To investigate if enhanced training counteracts the amnesic effect of interference with normal HIPP activity, Quiroz et al (2003) infused tetrodotoxin, the sodium channel blocker, into this structure immediately after IA training.…”

Androgens’ effects to enhance learning may be mediated in part through actions at estrogen receptor-β in the hippocampus

“…The hippocampus is an important brain region for cognitive behaviors and may be a target for androgens' actions (Kaut & Bunsey, 2001;Martinez et al, 2002). Further, ERβ, a possible substrate for androgens' actions, has been localized to the hippocampus (Kalita et al, 2005;Mehra et al, 2005;Shughrue et al, 1997).…”

“…The hippocampus mediates performance in the inhibitory avoidance task Martinez, Quirarte, Diaz-Cintra, Quiroz, & Prado-Alcala, 2002). Hippocampal integrity is important for performance in this task (Martinez et al, 2002). In addition, the inhibitory avoidance task is sensitive to androgen administration .…”

Induction of Long-Term Memory by Exposure to Novelty Requires Protein Synthesis: Evidence for a Behavioral Tagging

“…Given that the hippocampal region is an essential component of the circuit that detects and responds to new stimuli (Knight, 1996;Grunwald et al, 1998;Moncada and Viola, 2006) and that its pharmacological or surgical manipulation impairs memory formation of the inhibitory avoidance learning task (Bernabeu et al,1997;Taubenfeld et al, 2001;Martinez et al, 2002), the effects of the interaction between the spatial novel exploration and the inhibitory avoidance training in the rat hippocampus is a suitable behavioral design to evaluate the behavioral tagging hypothesis.…”