Differences between paired-pulse facilitation and long-term potentiation in the dorsal and ventral hippocampal CA1-prefrontal pathways of rats

• Published in: Brain research 2003-11, Vol.992 (1), p.142-145
• Main Authors: Izaki, Yoshinori, Takita, Masatoshi, Nomura, Masahiko, Akema, Tatsuo
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Central nervous system; Electric Stimulation; Electrophysiology; Fundamental and applied biological sciences. Psychology; Hippocampus - physiology; Hippocampus-prefrontal cortex pathway; In vivo; Long-term potentiation; Long-Term Potentiation - physiology; Male; Medial prefrontal cortex; Microelectrodes; Neural Pathways - physiology; Neuronal Plasticity - physiology; Paired-pulse facilitation; Posterior dorsal CA1; Prefrontal Cortex - physiology; Rat; Rats; Rats, Wistar; Synaptic Transmission - physiology; Ventral CA1; Vertebrates: nervous system and sense organs
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(03)03538-8

We studied the interaction between paired-pulse facilitation (PPF) and long-term potentiation (LTP) in the hippocampo-prefrontal cortex (PFC, prelimbic area) pathway, stimulating the ventral or posterior dorsal CA1 region (vCA1 or pdCA1). In the vCA1–PFC, the group averaged PPF did not change after the LTP induction, and there was a negative correlation between the post-LTP PPF change and LTP magnitude. In contrast, the post-LTP PPF of the pdCA1–PFC appeared to decrease significantly, and the PPF change was independent of the LTP magnitude. We found that there were at least two mechanisms of PPF regulation following LTP induction in the pathway resulting from extensive CA1 projections into the prelimbic area. The results imply that the CA1–PFC pathway regulates the PFC PPF quantitatively in LTP-dependent and independent manners, which depend on the local properties of the CA1 regions.