The Journal of comparative neurology
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These studies examined changes in the expression of pituitary adenylate cyclase-activating polypeptide (PACAP) in micturition reflex pathways after chronic cystitis induced by cyclophosphamide (CYP). In control Wistar rats, PACAP immunoreactivity was expressed in fibers in the superficial dorsal horn at all segmental levels examined (L1, L2, and L4-S1). Bladder afferent cells (40-45%) in the dorsal root ganglia (DRG; L1, L2, L6, and S1) from control animals also exhibited PACAP immunoreactivity. ⋯ No changes were observed in the L3-L5 DRG. These studies suggest that the neuropeptide, PACAP, may play a role in urinary bladder afferent pathways after visceral (urinary bladder) inflammation. Changes in PACAP expression after cystitis may play a role in altered visceral sensation (allodynia) and/or urinary bladder hyperreflexia in the clinical syndrome, interstitial cystitis.
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The lateral magnocellular nucleus of the anterior neostriatum (lMAN) is necessary for both initial learning of vocal patterns in developing zebra finches, as well as for modification of adult song under some circumstances. Lateral MAN is composed of two subregions: a core of magnocellular neurons and a surrounding shell composed primarily of parvocellular neurons. Neurons in lMAN(core) project to a region of motor cortex known as robust nucleus of the archistriatum (RA), whereas neurons in lMAN(shell) project to a region adjacent to RA known as dorsal archistriatum (Ad). ⋯ Because both auditory experience with an adult (tutor) song pattern and auditory feedback are essential to vocal learning, closed-loop pathways could serve as comparator circuits in which efferent commands, auditory feedback, and the memory of the tutor song are compared in an iterative fashion to achieve a gradual refinement of vocal production until it matches the tutor song. In addition, these circuits seem to have a strong integrative and limbic flavor. That is, the axonal connections of Ad neurons clearly include regions that receive inputs not only from somatosensory, visual, and auditory areas of cortex, but also from limbic regions, suggesting that they may be involved in higher order sensory processing, arousal, and motivation.