Hyperstriatum ventrale in pigeons: Effects of lesions on color-discrimination and color-reversal learning

Abstract

Previous lesion studies of color-reversal learning in pigeons show that an impairment results when (1) the tectofugal visual pathway is damaged at either the thalamic level (nucleus rotundus) or the telencephalic level (ectostriatum), or (2) the thalamofugal visual pathway is damaged at the telencephalic level (the visual Wulst). An impairment does not result, however, when the thalamic source of thalamofugal input (n. opticus principalis thalami or OPT) to the visual Wulst is damaged. These results suggest that the visual Wulst plays a role in color-reversal learning as a consequence of visual information routed from the tectofugal pathway via other visual areas in the telencephalon. One such area is the hyperstriatum ventrale (HV). In the present study, after ablation of the medial and lateral regions of HV, pigeons were trained postoperatively to discriminate between two colors presented simultaneously. After reaching criterion, the pigeons were required to perform a series of discrimination reversals in which the positive and negative stimuli were interchanged. Lesions of medial HV resulted in impaired performance of a color-discrimination task (i.e. original learning), but did not affect discrimination reversal. An impairment in color-reversal learning resulted from combined damage to lateral HV and the fronto-thalamic tract (FT), which carries ascending visual input from OPT to the visual Wulst. No deficits were observed when either lateral HV or FT were damaged alone. These findings suggest that both the thalamofugal and tectofugal pathways provide the visual Wulst with visual input relevant to color-reversal learning.

Sex-and Region-Dependent Expression of the Autism-Linked ADNP Correlates with Social- and Speech-Related Genes in the Canary Brain

“…M, formerly known as hyperstriatum ventral (HV) (Reiner et al 2004a), is a telencephalic region, part of the avian pallium (Reiner et al 2004a). Previous studies associated M with color discrimination in pigeons (Chaves and Hodos 1997) while HV relative size was found to significantly correlate with the rate of feeding innovation in birds (Timmermans et al 2000). In primates, a similar correlation was observed with the relative size of the neocortex (Timmermans et al 2000;Michael et al 2015).…”

Perineuronal satellite neuroglia in the telencephalon of New Caledonian crows and other Passeriformes: evidence of satellite glial cells in the central nervous system of healthy birds?

“…3 and 4). These telencephalic areas have been shown to form a neural circuit critical for audiovisual imprinting and passive avoidance learning in chicks (Horn, 1981; Horn, 2004; Cipolla-Neto, Horn & McCabe, 1982; Nakamori et al, 2010; Town & McCabe, 2011) and for colour-discrimination learning in pigeons (Chaves & Hodos, 1997) (though neither species present PGCs).…”

Afferent and efferent projections of the mesopallium in the pigeon (Columba livia)

“…However, the critical period for imprinting in chicks ends approximately 1 week after hatching (Bolhuis, 1991; Maekawa et al, 2007) and whether activation of the mesopallium and nidopallium still has the same effect in the adult is unknown. Chaves and Hodos (1997) reported that the medial mesopallium engages in color discrimination in adult pigeons. It is therefore speculated that the structural organization for imprinting in IMM is still maintained in adults and that new functions other than imprinting are added.…”