title: Visually-induced NGFI-A protein expression in the calbindin-, parvalbumin- and nitric oxide synthase-neuronal populations of the rat superior colliculus.
abstract: The expression of the immediate early gene NGFI-A in the nervous system is induced by sensory stimulation and seems to be related to long-term synaptic plasticity. We have used double-labeling immunohistochemistry to identify calbindin (CB)(+), parvalbumin (PV)(+) and neuronal nitric oxide synthase (nNOS)(+) neurons that also expressed the protein encoded by this immediate early gene after light-exposure on in the superficial layers of the rat superior colliculus (sSC). The majority of the NGFI-A(+) cells were not double-labeled for the tested markers. In the stratum zonale+stratum griseum superficiale (SZ/SGS), only 17.8%, 8.0% and 12.1% of NGFI-A(+) cells were also labeled for CB, PV or nNOS, respectively. In the stratum opticum (SO), only 10.5% of the NGFI-A(+) cells were also CB(+). Furthermore, only a small subset of each population expressed the NGFI-A protein after light-exposure. In the SZ/SGS, 35.7% of the CB(+), 32.1% of the PV(+) and 26.6% of the nNOS(+) neurons also expressed the NGFI-A. In the SO, 31.7% of the CB(+) neurons also expressed the NGFI-A. The proportional distribution of the nNOS(+)/NGFI-A(+) neurons throughout the SZ/SGS layers showed a slight but significant rostro-caudal gradient. No significant difference was observed for the other markers, indicating homogeneous activation of these populations throughout the retinotopic map. Our results suggest that the visually-driven NGFI-A expression is not restricted to a specific population of the sSC and that visual processing in this structure, as assessed by the expression of this candidate-plasticity protein, involves the activation of subsets of ascending and non-ascending projection neurons.
authors.affiliation: Laboratório de Neurobiologia Celular e Molecular, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, RJ 21949-900, Brazil. agiraldi@biof.ufrj.br
authors.forename: Arthur
authors.initials: A
authors.lastname: Giraldi-Guimarães
authors.forename: Rosalia
authors.initials: R
authors.lastname: Mendez-Otero
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D064026:Calbindins; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003623:Dark Adaptation / Q000502:physiology / Q000528:radiation effects; D051766:Early Growth Response Protein 1; D005786:Gene Expression Regulation / Q000502:physiology / Q000528:radiation effects; D017874:Immediate-Early Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D008027:Light; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D010320:Parvalbumins / Q000378:metabolism*; D010775:Photic Stimulation; D051381:Rats; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000528:radiation effects; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D013477:Superior Colliculi / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014795:Visual Pathways / Q000378:metabolism / Q000528:radiation effects
chemical_list: D015415:Biomarkers; D064026:Calbindins; D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D009419:Nerve Tissue Proteins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G; D014157:Transcription Factors; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat