Nucleus isthmi provides most tectal choline acetyltransferase in the frog Rana pipiens.
Up to 9 weeks following the removal of unilateral retinal input, choline acetyltransferase (ChAT) activity in the de-afferented tectal lobe is not significantly different from the intact tectal lobe. At 14 weeks, there is a 29% increase in the de-afferented side compared to the intact side. Following unilateral lesion of nucleus isthmi, ChAT activity in the tectal lobe ipsilateral to the lesion is approximately 30% of that measured in the contralateral lobe. Following bilateral n. isthmi lesion, ChAT activity in each tectal lobe is reduced by approximately 94% from intact tectal lobe controls. Thus, nucleus isthmi is the principal source of cholinergic input to the tectum.
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D011894:Rana pipiens; D013477:Superior Colliculi / Q000201:enzymology*; D013681:Tegmentum Mesencephali / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*
D002795:Choline O-Acetyltransferase