Abstract
Abstract: :
Purpose: To identify retinal neurons containing pituitary adenylate cyclase activating polypeptide (PACAP) and to determine whether they contain the biological clock protein, Period 1 (Per1) Methods:We used a transgenic mouse in which green fluorescent protein (GFP) was driven by the promoter for Per1 (Kuhlman et al., Neuroreport 11:1-4, 2000). Per1 was identified by an antibody against GFP; PACAP and vasoactive intestinal peptide (VIP) immunoreactivities (IR) were studied with commercially available antibodies. Results:PACAP-IR was found in small ganglion cells and one subtype of amacrine cell. The PACAP+ ganglion cell co-localized GFP-PER. PACAP-IR amacrine cells had round or oval perikarya located at different levels in proximal inner nuclear layer and processes that distributed to inner plexiform (IPL) sub-laminae 1,4 and 5. PACAP- and VIP-IR amacrines have similar morphology, although VIP+ amacrines did not send processes to IPL sublamina 5. No VIP+ ganglion cells were observed. Conclusion:PACAP+ neurons exist in mouse retina and their activity may be controlled by a biological clock. They are one of a number of retinal peptidergic neurons which stimulate adenylate cyclase.
Keywords: 557 retina: proximal(bipolar, amacrine, and ganglion cells) • 559 retinal connections, networks, circuitry • 488 neuropeptides