Connections of the bullfrog striatum: Efferent projections

• DOI: 10.1002/cne.902140310
• Publication Date: 2004-12-28T20:05:53Z
• Authors: Walter Wilczynski; R. Glenn Northcutt
• Keywords: Pretectal area; Medial forebrain bundle; Posterior commissure; Ventral striatum; Zona incerta

Abstract Autoradiographic and degeneration techniques were used to describe striatal efferents in the bullfrog (Rana catesbeiana) . Horseradish peroxidase (HRP) was then placed major terminal fields reveal cells responsible for these projections. Except small ventral eminence of lateral pallium immediately adjacent dorsal striatum, no pallial region receives a projection. Most descend forebrain bundle (LFB), passing through anterior entopedun‐cular nucleus, where one large fascicle decussates commissure innervates contralateral entopeduncular nucleus caudal striatum. A smaller exits LFB terminate ipsilateral amygdala. The remaining continue posterior with sparse projections thalamus, preoptic areas, tuberculum leaving at various points. At pretectal levels, some leave run dorsally, pole central thalamic into division portion nucleus. Efferents also caudal, superficial tegmental cell groups (nucleus profundus mesencephali isthmal reticular nucleus) before turning dorsomedially anterodorsal, anteroventral, rostral posterodorsal fields. projection continues levels but cannot be traced beyond. Tegmental HRP injections retrogradely fill striatum as well accumbens Pretectal only Anterior numerous all divisions, this filling may due interrupted fibers passage. Thus anuran which its input from nuclei relaying tectal toral input, can turn influence midbrain roof via several disynaptic pathways: pretectum, tegmentum, project directly tectum torus (Wilczynski Northcutt, ′77; Wilczynski, ′81). Additional trisynaptic routes connections parallel routes.