Characteristics of Learning and Memory Impairment Induced by ⊿9-Tetrahydrocannabinol in Rats

https://doi.org/10.1254/jjp.87.297Get rights and content
Under a Creative Commons license
open archive

Abstract

We investigated the characteristics of ⊿9-tetrahydrocannabinol (THC)-induced impairment of learning and memory using an 8-arm radial maze task, a water maze, a visual discrimination task with 2 figures and a passive avoidance test in rats. THC (6 mg /kg, i.p.) impaired spatial memory in the standard task of the 8-arm radial maze. THC (4-6 mg /kg, i.p.) selectively impaired working memory in a reference and working memory task of the 8-arm radial maze. Even at a dose of 10 mg /kg, THC did not impair spatial memory in the water maze. In addition, THC at a dose of 6 mg /kg, which had inhibitory effects in the 8-arm radial maze, did not affect performance in the visual discrimination task. These results indicate that at low doses (2 - 6 mg/kg), THC may not produce visual function abnormalities. THC impaired retrieval (6 mg /kg, i.p.) as well as acquisition (10 mg /kg, i.p.) in the passive avoidance test. The consolidation process was also impaired by i.c.v. injection (100 μ g), but not i.p. injection (6-10 mg /kg) of THC. These results suggest that THC-induced impairment of spatial memory is based on the selective impairment of working memory through its effects on acquisition and retrieval processes.

Cited by (0)

*

Corresponding author. FAX: +81-92-863-0389