The Tubular Striatum

Abstract

In the mid-19th century, a misconception was born, which understandably persists in the minds of many neuroscientists today. The eminent scientist Albert von Kölliker named a tubular-shaped piece of tissue found in the brains of all mammals studied to date, the tuberculum olfactoriumor what is commonly known as the olfactory tubercle (OT). In doing this, Kölliker ascribed "olfactory" functions and an "olfactory" purpose to the OT. The OT has since been classified as one of several olfactory cortices. However, further investigations of OT functions, especially over the last decade, have provided evidence for roles of the OT beyond olfaction, including in learning, motivated behaviors, and even seeking of psychoactive drugs. Indeed, research to date suggests caution in assigning the OT with a purely olfactory role. Here, I build on previous research to synthesize a model wherein the OT, which may be more appropriately termed the "tubular striatum" (TuS), is a neural system in which sensory information derived from an organism's experiences is integrated with information about its motivational states to guide affective and behavioral responses.

Extrinsic neuromodulation in the rodent olfactory bulb

“…The primary olfactory cortex, i.e., areas with direct OB input, comprises the anterior olfactory nucleus, tenia tecta, dorsal peduncular cortex, piriform cortex, olfactory tubercle, nucleus of the lateral olfactory tract, cortical amygdala, and lateral entorhinal area (Igarashi et al 2012 ; Neville and Haberly 2004 ; Wesson 2020 ).…”

Hierarchical cross-scale analysis identifies parallel ventral striatal networks coding for dynamic and stabilized olfactory reward predictions

“…Finally, the enhanced responsiveness to reward of the anticipatory ramping population compared to the CS-bound RP population adds to their differentiation. Potentially, such differentiations could map on the anterior-posterior gradients for PE value and reward representations found here, different olfactory and reward-related projection gradients (Ikemoto et al, 2015, Wesson, 2020), or direct- and indirect-pathway Tu neurons (Murata et al, 2015). Taken together, the different coding strategies, the non-overlapping neuronal clusters, the functional dissociation of the two RP signals and VTA, and the different responsiveness to reward, support the presence of parallel networks for stabilized and dynamic reward prediction in Tu.…”

PharmacoSTORM nanoscale pharmacology reveals cariprazine binding on Islands of Calleja granule cells

“…The highest abundance of dopaminergic fibers is known to be concentrated in the striatum 41 . Low-magnification broad topological examination of the striatal areas revealed the condensed accumulation of fluo-cariprazine-binding sites in the ventral part of the forebrain that is known as the tubular striatum 42 . This binding pattern was in striking contrast to the very weak fluo-cariprazine-binding density throughout the dorsal and ventral striatum (Fig.…”

“…Large-scale analysis and 3D reconstruction of ligand-binding sites revealed the preference of fluo-cariprazine toward a large continuous neuronal assembly, that is embedded in the tubular striatum 42 and corresponds to the anatomical structure of the Islands of Calleja. Previous studies, that attempted to discern the complex morphology of this brain region often relied solely on nuclear staining or the increased NADPH-diaphorase reactivity of this region 43 – 45 .…”