Cholinergic modulation of dopamine release and horizontal cell coupling in mudpuppy retina

Myhr, Karen L.; McReynolds, John S.

doi:10.1016/s0042-6989(96)00131-9

Cited by 10 publications

(11 citation statements)

References 24 publications

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“…It is possible that photoreceptors lack some binding element that paraformaldehyde can cross-link with DAF to retain activated DAF within the photoreceptors. The increased NO-IF in horizontal cells may be related to the uncoupling effects of cholinergic agonists that have been reported in horizontal cells in mudpuppy retina (Myhr & McReynolds, 1996). Thus there is no indication that fixation produces any artifactual production of NOIF or DAF activation and that in some cell types there can be a decrease in NO-IF in response to fixation.…”

Section: Aldehyde Fixation Of Dafmentioning

confidence: 72%

Imaging of nitric oxide in the retina

Eldred

Blute

2005

Vision Research

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Nitric oxide (NO) is the most widespread signaling molecule found in the retina in that it can be made by every retinal cell type. NO is able to influence a wide variety of synaptic mechanisms ranging from increasing or decreasing neurotransmitter release to the modulation of gap junction conductivity. Although biochemical methods can analyze overall levels of NO, such methods cannot indicate the specific cell types involved. In the last few years, fluorescent imaging methods utilizing diaminofluorescein have allowed the real-time visualization of neurochemically or light stimulated NO-induced fluorescence (NO-IF) in specific retinal cells. Recent experiments have shown that this NO-IF can be stabilized using paraformaldehyde fixation. This aldehyde stabilization has allowed the imaging of NO production in the dark and in response to light, as well as the neurochemical modulation of light stimulated NO production. The results of these studies indicate that NO is not always freely diffusible and that NO is largely retained in many cells which make it. The NO production in retina is highly damped in that in the absence of stimulation, the endogenous levels of NO production are extremely low. Finally, different neurochemical or light stimulation protocols activate NO production in specific cells and subcellular compartments. Therefore, although the NO signaling is widespread in retina, it is very selectively activated and has different functions in specific retinal cell types. The use of NO imaging will continue to play a critical role in future studies of the function of NO in retina and other neural systems.

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Section: Aldehyde Fixation Of Dafmentioning

confidence: 72%

Imaging of nitric oxide in the retina

Eldred

Blute

2005

Vision Research

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“…Cholinergic modulation of dopamine release has been found in the mudpuppy (Myhr and McReynolds, 1996), fish (Negishi and Drujan, 1979), tiger salamander (Hare and Owen, 1995), chick (Schwahn et al, 2000), and rabbit retinas (Neal et al, 2001). Despite these similarities, there are some species variations in the localization and function of cholinergic signaling components.…”

Section: Previous Localization Of Ach and Machrs In The Retina; Functmentioning

confidence: 99%

“…In the tiger salamander, Marshall and Werblin (1978) showed that ACh application uncoupled horizontal cells, consistent with the idea of cholinergic signaling in the outer retina. Studies in the salamander and mudpuppy retina later stated that this was due to an increased release of dopamine mediated by nAChRs (Hare and Owen, 1995;Myhr and McReynolds, 1996). However Myhr and McReynolds (1996) used fluphenazine as a dopaminergic antagonist, and since fluphenazine also antagonizes calmodulin, any cholinergic interaction with the NO signaling pathway would also have been blocked because activated calmodulin is required for NO synthesis by NOS.…”

Section: Previous Localization Of Ach and Machrs In The Retina; Functmentioning

confidence: 99%

Role of acetylcholine in nitric oxide production in the salamander retina

Cimini

Strang

Wotring

et al. 2008

J of Comparative Neurology

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Although acetylcholine is one of the most widely studied neurotransmitters in the retina, many questions remain about its downstream signaling mechanisms. In this study we initially characterized the cholinergic neurotransmitter system in the salamander retina by localizing a variety of cholinergic markers. We then examined the link between both muscarinic and nicotinic receptor activation and nitric oxide production by using immunocytochemistry for cyclic guanosine monophosphate (cGMP) as an indicator. We found a large increase in cGMP-like immunoreactivity (cGMP-LI) in the inner retina in response to muscarinic (but not nicotinic) receptor activation. Based on the amplification of mRNA transcripts, receptor immunocytochemistry, and the use of selective antagonists, we identified these receptors as M2 muscarinic receptors. Using double-labeling techniques, we established that these increases in cGMP-LI were seen in GABAergic but not cholinergic amacrine cells, and that the increases were blocked by inhibitors of nitric oxide production. The creation of nitric oxide in response to cholinergic receptor activation may provide a mechanism for modulating the well-known mutual interactions of acetylcholine-glycine-GABA in the inner retina. As GABA and glycine are the primary inhibitory neurotransmitters in the retina, signaling pathways that modulate their levels or release will have major implications for the processing of complex stimuli by the retina.

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“…Nitric oxide increases the levels of cyclic guanosine monophosphate in overlapping populations of retinal cells 27 . Nicotine also serves as a modulatory transmitter, increasing dopamine release and modulating horizontal cell coupling 28 …”

Section: Discussionmentioning

confidence: 99%

“…27 Nicotine also serves as a modulatory transmitter, increasing dopamine release and modulating horizontal cell coupling. 28 Nicotine addiction leads to withdrawal symptoms in many persons who quit smoking. Nicotine receptors in the central nervous system are located mainly in presynaptic membrane and in that way they regulate the release of several neurotransmitters.…”

Section: Discussionmentioning

confidence: 99%