Influence of NO downregulation on oscillatory evoked responses in developing rat superior colliculus
| Autor: | Jamila Aı̈toubah, Jean-Paul Guillemot, Yao-Fang Tan, Frédéric Bretzner, Svetlana Shumikhina, Sylvain Chemtob, Stephen K. Itaya, Stéphane Molotchnikoff |
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| Rok vydání: | 2002 |
| Předmět: |
medicine.medical_specialty
Superior Colliculi Arginine Down-Regulation Evoked field Nitric Oxide Synthase Type I Nitric Oxide Nitric oxide chemistry.chemical_compound Developmental Neuroscience Downregulation and upregulation Internal medicine medicine Animals Rats Long-Evans Enzyme Inhibitors Neurotransmitter Microinjection Evoked Potentials gamma-Aminobutyric Acid Neurons biology Superior colliculus Iontophoresis Electric Stimulation Rats Nitric oxide synthase Endocrinology NG-Nitroarginine Methyl Ester chemistry biology.protein Nitric Oxide Synthase Neuroscience Developmental Biology |
| Zdroj: | Brain research. Developmental brain research. 138(2) |
| ISSN: | 0165-3806 |
| Popis: | Nitric oxide (NO) is involved in neuronal transmission by modulating neurotransmitter release in adults and in stabilizing synaptic connections in developing brains. We investigated the influence of downregulation of NO synthesis on oscillatory components of ON and OFF evoked field potentials in the rat superior colliculus. NO synthesis was decreased by inhibiting nitric oxide synthase (NOS) with an acute microinjection of Nω-nitro- l -arginine methyl ester ( l -NAME). The study focuses on rhythmic activity by analyzing fast Fourier transform (FFT). Collicular responses were recorded in anesthetized rats, at postnatal days (PND) 13–19 and adults. This time window was chosen because it is centered on eye opening. NO downregulation resulted in a dual effect depending on age and response-type. NO synthesis inhibition decreased the magnitude of oscillations in ON responses in the youngest animals (PND13–14), whereas oscillations of frequencies higher than 20 Hz in OFF responses were increased in all age groups of developing rats. In adults NO downregulation increased oscillations in ON responses and decreased oscillations in OFF responses. l -Arginine was used to increase NOS activity and its injection produced effects opposite to those seen with l -NAME. Slow oscillatory components (7–12 Hz) were unaffected in all experiments. Our data together with results reported in the literature suggest that rhythmic patterns of activity are NO-dependent. |
| Databáze: | OpenAIRE |
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