Search bioRxiv⌕ Search

Biology subjects

Bromberg-Martin, E. S.

Publications and source records attributed to Bromberg-Martin, E. S..

6 recordsLinked to original sources

A prefrontal cortex-hypothalamus circuit for heart rate control in non-human primates

Humans exhibit changes in heart rate during cognitive and emotional events, and dysregulation of this brain-heart coupling is a hallmark of many psychiatric disorders. Yet, how circuits that regulate cognition exert direct control over heart physiology remains poorly understood, particularly in primates. Here, we identify a prefrontal-hypothalamic circuit that exerts powerful, bidirectional control over heart rate in monkeys. We show that electrical stimulation of a small ventral subregion within the ventrolateral prefrontal cortex (area 47/12; a12) evokes rapid and robust decreases in heart rate and increases heart rate variability, whereas neighboring prefrontal regions produce weaker or no effects. And a12 neurons are coupled to heart rate on a moment-by-moment basis. Anatomical tracing data reveal projections from a12 to a circumscribed region of lateral hypothalamus (LHA), and stimulation of this LHA target recapitulates the cardiac effects of prefrontal activation. Consistent with a prefrontal-to-hypothalamus system for heart rate control, stimulation of LHA produces faster, stronger, state-independent heart effects, whereas stimulation of a12 produces effects that are sensitive to internal states. Oppositely to its activation, chemogenetic inactivation of a12 or its projections to LHA increases heart rate, demonstrating that this pathway can provide tonic inhibitory control over cardiac function. To make steps towards a more cell-type-specific and minimally invasive causal control of this circuit, we developed a primate sonogenetic approach based on ultrasound activation of CaMKII+ neurons virally transduced with TRPV1. Sonogenetic stimulation of a12 produced increases in heart rate variability, and these effects were attenuated by inactivation of LHA. Finally, we found that sonogenetic and chemogenetic perturbation of the same prefrontal region during a value-based decision-making task bidirectionally alters risky decision making. Together, our work identifies how a12 regulates heart rate and cognition, revealing a mechanistic substrate for brain-body interactions and a potential therapeutic target for disorders of cognitive-autonomic dysregulation.

neuroscience↗

Why do we seek information about the future? On the origins of subjective value without instrumental value

Why do we want to know the future? Humans and many animals pay for information to predict uncertain rewards, even when they cannot control them. The reason for this conserved yet seemingly paradoxical preference - "subjective value without instrumental value" - remains unknown. Here we develop a normative framework to explain the origins of such preferences, their persistence across species, and their contributions to survival. We formalize and evaluate theories that explain subjective value as originating from an adaptive estimate of advantage for solving core computational problems in naturalistic environments. We show that human and animal subjective values are remarkably well suited to solve these problems, accomplishing the goals of multiple theories simultaneously. We derive novel forms of information to enable existing theories to be dissociated, and show that pooling their subjective values improves performance across diverse environments. Thus, organisms may value information because it pays diverse dividends in nature.

neuroscience↗

Representations of information value in mouse orbitofrontal cortex during information seeking

Animals are motivated to seek information that does not influence reward outcomes, suggesting that information has intrinsic value. We have developed an odor-based information seeking task that reveals that mice choose to receive information even though it does not alter the reward outcome. Moreover, mice are willing to pay for information by sacrificing water reward, suggesting that information is of intrinsic value to a mouse. We used a microendoscope to reveal neural activity in orbitofrontal cortex (OFC) while mice learned the information seeking task. We observed the emergence of distinct populations of neurons responsive to odors predictive of information and odors predictive of water reward. A latent variable model recapitulated these different representations in the low-dimensional dynamics of OFC neuronal population activity. These data suggest that mice have evolved separate pathways to represent the intrinsic value of information and the extrinsic value of water reward. Thus, the desire to acquire knowledge is observed in mice, and the value of this information is represented in the OFC. The mouse now provides a facile experimental system to study the representation of the value of information, a higher cognitive variable.

neuroscience↗

Dorsal raphe neurons signal integrated value during multi-attribute decision-making

The dorsal raphe nucleus (DRN) is implicated in psychiatric disorders that feature impaired sensitivity to reward amount, impulsivity when facing reward delays, and risk-seeking when grappling with reward uncertainty. However, whether and how DRN neurons signal reward amount, reward delay, and reward uncertainty during multi-attribute value-based decision-making, where subjects consider all these attributes to make a choice, is unclear. We recorded DRN neurons as monkeys chose between offers whose attributes, namely expected reward amount, reward delay, and reward uncertainty, varied independently. Many DRN neurons signaled offer attributes. Remarkably, these neurons commonly integrated offer attributes in a manner that reflected monkeys overall preferences for amount, delay, and uncertainty. After decision-making, in response to post-decision feedback, these same neurons signaled signed reward prediction errors, suggesting a broader role in tracking value across task epochs and behavioral contexts. Our data illustrate how DRN participates in integrated value computations, guiding theories of DRN in decision-making and psychiatric disease.

neuroscience↗

A neural mechanism for conserved value computations integrating information and rewards

Behavioral and economic theory dictates that we decide between options based on their values. However, humans and animals eagerly seek information about uncertain future rewards, even when this information does not provide any objective value. This implies that decisions can be made by endowing information with subjective value and integrating it with the value of extrinsic rewards, but the mechanism is unknown. Using a novel multi-attribute decision making task we found that human and monkey value judgements are regulated by strikingly conserved computational principles, including how they compute the value of information and scale it with informations timing and ability to resolve a specific form of uncertainty. We then identified a neural substrate in a highly conserved and ancient structure, the lateral habenula (LHb). LHb neurons signal the subjective value of choice options integrating the value of information with extrinsic rewards, and LHb activity both predicts and causally influences online decisions. Key input regions to LHb provide the necessary ingredients for these computations, but do not themselves signal an integrated value signal to guide multi attribute decisions. Our data thus identifies neural mechanisms of the conserved computations underlying multi-attribute, value-based decisions to seek information about the future.

neuroscience↗

A neural network for information seeking

Humans and other animals often show a strong desire to know the uncertain rewards their future has in store, even when they cannot use this information to influence the outcome. However, it is unknown how the brain predicts opportunities to gain information and motivates this information seeking behavior. Here we show that neurons in a network of interconnected subregions of primate anterior cingulate cortex and basal ganglia predict the moment of gaining information about uncertain rewards. Spontaneous increases in their information prediction signals are followed by gaze shifts toward objects associated with resolving uncertainty, and pharmacologically disrupting this network reduces the motivation to seek information. These findings demonstrate a cortico-basal ganglia mechanism responsible for motivating actions to resolve uncertainty by seeking knowledge about the future.

neuroscience↗