Abrupt changes in the patterns and complexity of anterior cingulate cortex activity when food is introduced into an environment

Abstract

Foraging typically involves two distinct phases, an exploration phase where an organism explores its local environment in search of needed resources and an exploitation phase where a discovered resource is consumed. The behavior and cognitive requirements of exploration and exploitation are quite different and yet organisms can quickly and efficiently switch between them many times during a foraging bout. The present study investigated neural activity state dynamics in the anterior cingulate sub-region of the rat medial prefrontal cortex (mPFC) when a reliable food source was introduced into an environment. Distinct and largely independent states were detected using a Hidden Markov Model (HMM) when food was present or absent in the environment. Measures of neural entropy or complexity decreased when rats went from exploring the environment to exploiting a reliable food source. Exploration in the absence of food was associated with many weak activity states, while bouts of food consumption were characterized by fewer stronger states. Widespread activity state changes in the mPFC may help to inform foraging decisions and focus behavior on what is currently most prominent or valuable in the environment.

Activation of Pyramidal Neurons in Mouse Medial Prefrontal Cortex Enhances Food-Seeking Behavior While Reducing Impulsivity in the Absence of an Effect on Food Intake

“…In contrast, the assays in which we did not observe an effect are relatively non-demanding, and do not require a significant degree of learning or goal/value updating. Thus, increasing PN activation in the medial prefrontal cortex through DREADD signaling, above the level that might be observed during behavioral engagement in less cognitively demanding tasks such as food consumption (Caracheo et al, 2013 ), does not produce any change in behavioral output. However, during tasks requiring higher cognitive demand (Caracheo et al, 2013 ), increasing the gain of select PN within the frontal cortex has distinct behavioral consequences.…”

Distributed representations of action sequences in anterior cingulate cortex: A recurrent neural network approach

“…Although a handful of computational models have simulated ACC function previously (e.g., Alexander & Brown, 2011;Botvinick et al, 2001;Brown & Braver, 2005;Holroyd & Coles, 2002, 2008Holroyd & McClure, 2015;Holroyd, Yeung, Coles, & Cohen, 2005;Khamassi, et al, 2011;Silvetti et al, 2011;Verguts, 2017;Verguts et al, 2015;Yeung et al, 2004), to our knowledge none of these models have examined the essential role of ACC in encoding task execution as distributed representations that evolve dynamically with time (Balaguer-Ballester et al, 2011;Caracheo et al, 2013;Durstewitz et al, 2010;Lapish et al, 2008). Our simulations are thus the first to provide a formal account of this crucial aspect of ACC function.…”

“…Recently, Jeremy Seamans and colleagues have systematically investigated the activity of ACC neurons during the execution of task sequences (Balaguer-Ballester, Lapish, Seamans, & Durstewitz, 2011;Caracheo, Emberly, Hadizadeh, Hyman, & Seamans, 2013;Durstewitz, Vittoz, Floresco, & Seamans, 2010;Hyman, Ma, Balaguer-Ballester, Durstewitz, & Seamans, 2012;Hyman, Whitman, Emberly, Woodward, & Seamans, 2013;Lapish, Durstewitz, Chandler, & Seamans, 2008;Ma, Hyman, Lindsay, Phillips, & Seamans, 2014;. Their work focuses on distributed patterns of activity that characterize entire ensembles of neurons, rather than on the responses of the individual neurons that comprise the ensembles.…”

“…On this view, ACC network activity tracks task progression through a task-dependent frame of reference, or Btask space^ (Lapish et al, 2008), toward the animal's goal . The network activity is especially sensitive to transitions through subcomponents of cognitive tasks (Balaguer-Ballester et al, 2011) and is accompanied by abrupt transitions in the state space when the animal learns new rules (Durstewitz et al, 2010) or is exposed to important environmental changes (Caracheo et al, 2013). ACC network activity also discriminates between task sequences more accurately than comparable activity in the dorsal striatum (Ma, Hyman, Lindsay, et al, 2014;, and can be distinguished from the function of the hippocampus, which famously encodes sequences related to spatial navigation and other temporally organized events (Hyman et al, 2012).…”

Integrating Spatial Working Memory and Remote Memory: Interactions between the Medial Prefrontal Cortex and Hippocampus

“…In fact, this effect was so consistent and powerful that we were able to decode an animal’s environmental context based solely on mPFC ensemble states [19]. If we expand our concept of a context to one that does not necessarily need to be only spatial, we see that, in fact, similar results, i.e., large changes in mPFC ensemble states, have also been found with changes in behavioral sequence [42,44], task phase [45], rules [46], or reward location [47]. All of these differences can be viewed as changes of a larger context representation; in many cases, the context may be cognitively-based, or, in the absence of a clear task, it may be spatially-based.…”