Biology subjects

Papale, A. E.

Publications and source records attributed to Papale, A. E..

4 recordsLinked to original sources

bioRxiv2025

Prefrontal default-mode network interactions with posterior hippocampus during exploration

Hippocampal maps and ventral prefrontal cortex (vPFC) value and goal representations support foraging in continuous spaces. How might hippocampal-vPFC interactions control the balance between behavioral exploration and exploitation? Using fMRI and reinforcement learning modeling, we investigated vPFC and hippocampal responses as humans explored and exploited a continuous one-dimensional space, with out-of-session and out-of-sample replication. The spatial distribution of rewards, or value landscape, modulated activity in the hippocampus and default network vPFC subregions, but not in ventrolateral prefrontal control subregions or medial orbitofrontal limbic subregions. While prefrontal default network and hippocampus displayed higher activity in less complex, easy-to-exploit value landscapes, vPFC-hippocampal connectivity increased in uncertain landscapes requiring exploration. Further, synchronization between prefrontal default network and posterior hippocampus scaled with behavioral exploration. Considered alongside electrophysiological studies, our findings suggest that locations to be explored are identified through coordinated activity binding prefrontal default network value representations to posterior hippocampal maps. Significance StatementThe ventral prefrontal cortex represents goals and values, while the hippocampus contains maps of physical and abstract spaces. In recent years, neuroscientists have sought to understand how hippocampal-prefrontal interactions help us to solve complex problems such as deciding whether to exploit known rewards or explore in search of better alternatives. Using functional magnetic resonance imaging and reinforcement learning modeling, we examine these interactions as humans explore and exploit an environment with a complex distribution of rewards or value landscape. We describe how this value landscape modulates activity and connectivity between prefrontal cortex and hippocampus, controlling the balance between exploration and exploitation.

neuroscience↗

bioRxiv2023

Symmetry in frontal but not motor and somatosensory corticocortical and corticostriatal circuitry

Neocortex and striatum are topographically organized for sensory and motor functions. While sensory and motor areas are lateralized for touch and motor control, respectively, frontal areas are involved in decision making, where lateralization of function may be less important. This study contrasted the topographic precision of cell type-specific ipsilateral and contralateral cortical projections while varying the injection site location in transgenic mice of both sexes. While sensory cortical areas had strongly topographic outputs to ipsilateral cortex and striatum, they were weaker and not as topographically precise to contralateral targets. Motor cortex had somewhat stronger projections, but still relatively weak contralateral topography. In contrast, frontal cortical areas had high degrees of topographic similarity for both ipsilateral and contralateral projections to cortex and striatum. Corticothalamic organization is mainly ipsilateral, with weaker, more medial contralateral projections. Corticostriatal computations might integrate input outside closed basal ganglia loops using contralateral projections, enabling the two hemispheres to act as a unit to converge on one result in motor planning and decision making. Significance StatementEach cerebral hemisphere is responsible for sensation and movement of the opposite side of the body. Many axonal projections cross the midline to target contralateral areas. Crossed corticocortical, corticostriatal, and corticothalamic projections originate from much of neocortex, but how these projections vary across cortical regions and cell types is unknown. We quantify differences in the strength and targeting of ipsilateral and contralateral projections from frontal, motor, and somatosensory areas. The contralateral corticocortical and corticostriatal projections are proposed to play a larger role in frontal areas than in sensory or motor ones as a circuit basis for unifying computation across hemispheres in motor planning, while contralateral connectivity plays a smaller role in sensory and motor processing.

neuroscience↗

bioRxiv2019

Divergent neural pathways emanating from the lateral parabrachial nucleus mediate distinct components of the pain response

The lateral parabrachial nucleus (lPBN) is a major target of spinal projection neurons conveying nociceptive input into supraspinal structures. However, the functional role of distinct lPBN efferents for diverse nocifensive responses have remained largely uncharacterized. Here, we show that two populations of efferent neurons from different regions of the lPBN collateralize to distinct targets. Activation of efferent projections to the ventromedial hypothalamus (VMH) or lateral periaqueductal gray (lPAG) drive escape behaviors, whereas the activation of lPBN efferents to the bed nucleus stria terminalis (BNST) or central amygdala (CEA) generates an aversive memory. Finally, we provide evidence that dynorphin expressing neurons span cytoarchitecturally distinct domains of the lPBN to coordinate these distinct aspects of the nocifensive response.\n\nHIGHLIGHTSSpatially segregated neurons in the lPBN collateralize to distinct targets.\n\nDistinct output pathways give rise to separate aspects of the pain response.\n\nDynorphin neurons within the lPBN convey noxious information across subdivisions.\n\neTOC BLURBChiang et al. reveal that neurons in spatially segregated regions of the lateral parabrachial nucleus collateralize to distinct targets, and that activation of distinct efferents gives rise to separate components of the nocifensive response.

neuroscience↗

bioRxiv2018

Cell type-specific variation of somatotopic precision across corticostriatal projections

The striatum shows general topographic organization and regional differences in behavioral functions. How corticostriatal topography differs across cortical areas and cell types to support these distinct functions is unclear. This study contrasted corticostriatal projections from two layer 5 cell types, intratelencephalic (IT-type) and pyramidal tract (PT-type) neurons, using viral vectors expressing fluorescent reporters in Cre-driver mice. Long-range corticostriatal projections from sensory and motor cortex are somatotopic, with a decreasing somatotopic specificity as injections move from sensory to motor and frontal areas. Somatotopic organization differs between IT-type and PT-type neurons, including injections in the same site, with IT-type neurons having higher somatotopic stereotypy than PT-type neurons. Furthermore, IT-type projections from interconnected cortical areas have stronger correlations in corticostriatal targeting than PT-type projections do. Thus, as predicted by a long-standing basal ganglia model, corticostriatal projections of interconnected cortical areas form parallel circuits in basal ganglia-thalamus-cortex loops.

neuroscience↗