Septo-hippocampal pathway necessary for dentate theta production.

摘要: Abstract In acute experiments in urethane-anaesthetized rabbits a small lesion at the septo-hippocampal border, from 0.8 to 1.5 mm midline, abolished theta activity ipsilaterally. This severed fibres lateral part of medial septal nucleus. Lesions main body fimbria or dorsal fornix, alvear bundle and perforant path hippocampal commissures failed change dentate activity. Theta also survived establishment 2 wide ‘gate’ near rostral pole hippocampus; gate was produced by cutting medially adjoining tissue fornix laterally tissue. Cuts behind showed successive reduction when passed beyond threshold depth about mm. The degree appeared dependent upon amount destroyed below this level. Thus, importance for production seem run through bottleneck just behinf septum. Their further course is found basal on its aspect parts CA3 (lower blade) hilus fascia. Because whole area had be block all activity, it suggested that are relatively dispersed within region.