Hippocampus and parahippocampal areas constitute the medial temporal lobe (MTL). The hippocampus is an essential component of the human memory network. It is integral to the synthesis of learned information as well as information recovery during retrieval, and may be involved in spatial learning abilities200. fMRI has been used to evaluate visuospatial memory during abstinence from nicotine in adolescent smokers with and without PEMCS185. Adolescent smokers with PEMCS experienced greater nicotine withdrawal related deficits in immediate and delayed visuo-spatial memory relative to adolescent smokers with no PEMCS. Among adolescent smokers with PEMCS, nicotine withdrawal was associated with increased activation of the left parahippocampal gyrus during early recognition testing, and increased activation of the hippocampus bilaterally during delayed recognition testing of the visuo-spatial stimuli. These findings are clinically consistent with prior preclinical studies suggesting alterations in hippocampal architecture associated with combined prenatal and adolescent exposure to cigarette smoke and concomitant deficits in visuo-spatial memory201.
