Bilateral projection of nigro-collicular neurons: An electrophysiological analysis in the rat

Deniau, Jean-Michel; Guyader, C. Hammond-Le; Féger, J.; McKenzie, Jo

doi:10.1016/0304-3940(77)90163-x

Cited by 50 publications

(9 citation statements)

References 19 publications

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“…The observation that lesion-induced neurochemical changes in the contralateral superior colliculus could only be obtained using measurements of evoked GABA release (and even then only after the combined lesions) highlights the probability that the evoked release protocol offers much greater sensitivity than measures of GABA content alone. Together with the fact that hypertrophy of nigral neurons was restricted to the ipsilateral side, it also reinforces the idea that the nigrotectal projection is partially crossed (Deniau et al, 1977;Graybiel, 1978;Beckstead et al, 1979;Wright and Arbuthnott, 1980;Harting et al, 1988). However, it should be remembered that in otherwise naive animals, the maximum detectable contribution of nigrotectal terminals to the available pool of releasable GABA from within the ipsilateral tectum is only of the order of 25 % .…”

Section: Combined Cortical and Cp Lesionssupporting

confidence: 76%

Lesions of the Cerebral Cortex and Caudate‐Putamen Enhance GABA Function in the Rat Superior Colliculus

Kilpatrick

Neal

Pearson

et al. 1991

Eur J of Neuroscience

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Unilateral lesions of the rat frontal cortex were made either alone or in combination with the caudate-putamen in order to examine (a) their morphological influence on the substantia nigra and (b) their neurochemical influence on GABA function in the superior colliculus. One to two months following the combined lesion, neuronal somata in the ipsilateral pars reticulata of the substantia nigra were clearly hypertrophied (+ 30%). Morphological changes in the substantia nigra were not evident contralaterally or in animals bearing only cortical lesions. One to two months following cortex-only lesions, no significant alterations in tectal GABA concentration were observed. However, the combined lesion induced elevations of GABA within both the medial and lateral sectors of the intermediate and deep layers of the superior colliculus. This effect was restricted to the ipsilateral side and was most pronounced in lateral sectors. The vast majority of GABA released from superfused control tectal slices by a depolarizing stimulus (35 mM KCl) was calcium-dependent. Such evoked GABA release from ipsilateral tectal slices was significantly reduced (- 25%) by unilateral lesions of the substantia nigra, a structure that is known to provide GABA-containing inputs to the tectum. In contrast, cortical lesions alone significantly enhanced the evoked tectal GABA release (+ 66%), although their influence was again confined to the ipsilateral side. Combined lesions of the cerebral cortex and caudate-putamen significantly enhanced the evoked GABA release from tectal slices in both hemispheres but the changes were most marked ipsilaterally (+ 147%). It is suggested that the hypertrophy of GABA-containing nigrotectal somata seen after removal of corticostriatal, corticotectal and in particular GABA-containing striatonigral fibres may reflect concomitant increases in GABA synthesis within and/or sprouting of nigrotectal terminals.

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Section: Combined Cortical and Cp Lesionssupporting

confidence: 76%

Lesions of the Cerebral Cortex and Caudate‐Putamen Enhance GABA Function in the Rat Superior Colliculus

Kilpatrick

Neal

Pearson

et al. 1991

Eur J of Neuroscience

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“…A second set of studies suggesting a broader role for SNr input to the SC examined the anatomy and physiology of this input. First, while the disinhibition model is based on ipsilaterally projecting (i.e., "uncrossed") nigrotectal neurons, some ("crossed") nigrotectal neurons project contralaterally (Beckstead et al 1981;Chevalier et al 1981;Deniau et al 1977;Gerfen et al 1982;Jayaraman et al 1977;Liu and Basso 2008) and a small number project to both SCs (Cebrián et al 2005). Given that crossed nigrotectal projections are also inhibitory, they would appear to promote movements ipsiversive to the phasically inactivated SNr, inconsistent with the disinhibition model.…”

Section: Gabaergic Input To Superior Colliculus From Substantia Nigramentioning

confidence: 99%

An integrative role for the superior colliculus in selecting targets for movements

Wolf

Lintz

Costabile

et al. 2015

Journal of Neurophysiology

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-A fundamental goal of systems neuroscience is to understand the neural mechanisms underlying decision making. The midbrain superior colliculus (SC) is known to be central to the selection of one among many potential spatial targets for movements, which represents an important form of decision making that is tractable to rigorous experimental investigation. In this review, we first discuss data from mammalian models-including primates, cats, and rodents-that inform our understanding of how neural activity in the SC underlies the selection of targets for movements. We then examine the anatomy and physiology of inputs to the SC from three key regions that are themselves implicated in motor decisions-the basal ganglia, parabrachial region, and neocortex-and discuss how they may influence SC activity related to target selection. Finally, we discuss the potential for methodological advances to further our understanding of the neural bases of target selection. Our overarching goal is to synthesize what is known about how the SC and its inputs act together to mediate the selection of targets for movements, to highlight open questions about this process, and to spur future studies addressing these questions.

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“…Since the pioneering studies of Deniau et al (1977) and Faull and Mehler (1978), who described segregated nigrothalamic and nigrotectal projections, several attempts have been made to subdivide the SNR based on the organization of its efferent projections with limited success (Beckstead and Frankfurter, 1982;Francois et al, 1984c;Kemel et al, 1988;Deniau and Chevalier, 1992). Spatially separate regions were identified within the SNR that project predominantly to either the thalamus or the superior colliculus (rat: Gerfen et al, 1985;cat: Kemel et al, 1988;monkey: Beckstead and Frankfurter, 1982;Francois et al, 1984~).…”

Section: Compartmentation Of the Substantia Nigra Pars Reticulatamentioning

confidence: 99%

Parvalbumin‐containing GABAergic neurons in the basal ganglia output system of the rat

Rajakumar

Elisevich

Flumerfelt

1994

J of Comparative Neurology

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The output of the basal ganglia is directed through the entopeduncular nucleus (EPN) and the substantia nigra pars reticulata (SNR) and pars lateralis (SNL), which provide a gamma-aminobutyric acidergic (GABAergic) projection to various nuclei of the thalamus and brainstem. Although many neurons within the SNR and EPN have been described as modality specific, the morphological and neurochemical similarities preclude their precise identification. In the present study, the immunocytochemical localization of parvalbumin, a calcium-binding protein, is used in combination with axonal tracing to verify neuronal heterogeneity within the SNR, SNL, and EPN. The results reveal that the majority of neurons in all three centers contain parvalbumin. The parvalbumin-containing neurons are distributed in the caudal two-thirds of the EPN, the rostral part of the SNL, and the lateral two-thirds of the entire rostrocaudal extent of the SNR, the areas involved in sensorimotor function of the basal ganglia. Moreover, the nigrothalamic, nigrocollicular, and EPN-thalamic neurons possess parvalbumin immunoreactivity, whereas the EPN-habenular neurons are devoid of parvalbumin immunoreactivity. The results indicate a neurochemical heterogeneity within the GABAergic output neurons of the basal ganglia and suggest that the parvalbumin-containing neurons of the SNR, SNL, and EPN are the tonically active output neurons that form a major link in the disinhibitory neuronal circuit of the basal ganglia, especially that concerned with sensorimotor function.

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Bilateral projection of nigro-collicular neurons: An electrophysiological analysis in the rat

Cited by 50 publications

References 19 publications

Lesions of the Cerebral Cortex and Caudate‐Putamen Enhance GABA Function in the Rat Superior Colliculus

Lesions of the Cerebral Cortex and Caudate‐Putamen Enhance GABA Function in the Rat Superior Colliculus

An integrative role for the superior colliculus in selecting targets for movements

Parvalbumin‐containing GABAergic neurons in the basal ganglia output system of the rat

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