Send to

Choose Destination
See comment in PubMed Commons below
Brain Res. 1998 Jan 19;781(1-2):167-81.

Serotonin modulates induced synaptic activity in the optic tectum of the frog.

Author information

School of Biological Sciences, University of Kentucky, Lexington, KY 40506, USA.


The extent to which retinal signals are modulated at central sites is unknown. We sought to determine the effects of serotonin, a neurotransmitter present in the retinorecipient layers of the frog tectum, on retinotectal transmission. Acute electrical stimulation delivered to the retinorecipient layer of optic tectum brain slices was used to model the activation of tectal neurons by visual inputs. This stimulation evoked either a monosynaptic or a polysynaptic current response in patch-clamped tectal neurons. External application of serotonin blocked both of these induced currents as did 5-carbotryptamine (5-CT), a nonselective agonist of 5-HT1 receptors. Alpha-methylserotonin, a nonselective agonist of 5-HT2 receptors, also blocked polysynaptic responses but was less effective than either serotonin or 5-CT in blocking monosynaptic ones. Lateral synaptic interactions between tectal cells, modeled by acute electrical stimulation in the main cellular layer of the tectum, were also blocked by serotonin, 5-CT or alpha-methylserotonin. The presented data suggest that endogenous serotonin may strongly affect visual signal processing by modulating synaptic transmission between both the retina and the tectum as well as between tectal neurons. This modulation is likely to be due, at least in part, to a demonstrated outward current induced by serotonin in a subpopulation of tectal cells.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center