Disconnection of the amygdala central nucleus and the substantia innominata/nucleus basalis magnocellularis disrupts performance in a sustained attention task.

Abstract

The basal forebrain cholinergic system is broadly implicated in the regulation of attention. Disruptions in the function of this system produce impairments in many attentional functions, including the performance of well-learned responses under increased attentional load, and the surprise-induced enhancement of learning rate. Similarly, lesions of the amygdala central nucleus (CeA) have been found to impair attentional function in some circumstances. Here we examined the effects of lesions that disconnected CeA from the cholinergic substantia innominata/nucleus basalis magnocellularis (SI/nBM) on performance in a modified five-choice serial reaction time (5CSRT) task, thought to assess selective or sustained attention. The lesions impaired performance under conditions of increased attentional load, suggesting that a circuit that includes CeA and SI/nBM regulates these aspects of attention.

Effects of dorsal or ventral medial prefrontal cortical lesions on five-choice serial reaction time performance in rats

“…On the whole, this favoring of CRF cues was not affected by the attentional challenges themselves, except that reduction of the ready signal duration to 1 s in the ready signal duration challenge substantially suppressed many measures of responding to the CRF cues. Thus, it is uncertain whether the reduced performance to PRF cues relative to CRF cues in that test reflected a reduced allocation of attention to the PRF cues for purposes of controlling action [13,14,24,29] or simply lower associative strength. Regardless, it is notable that whereas the effects of the dorsal mPFC lesion on the distribution of responding to CRF and PRF cues were negligible (e.g., there were no significant lesion X reinforcement contingency interactions for any of the measures in either of the challenges), rats with ventral mPFC lesions failed to show differential responding to CRF and PRF cues in both of the attentional challenges.…”

Interpersonal early‐life trauma alters amygdala connectivity and sustained attention performance

“…Significant evidence points to an impact of I‐ELT on sustained attention ability (De Bellis, Woolley, & Hooper, 2013; DePrince, Weinzierl, & Combs, 2009; Kaplow, Hall, Koenen, Dodge, & Amaya‐Jackson, 2008; Navalta, Polcari, Webster, Boghossian, & Teicher, 2006; Porter, Lawson, & Bigler, 2005; Samuelson, Krueger, Burnett, & Wilson, 2010), yet no study to date has examined how I‐ELT‐related amygdala dysregulation may contribute to impairments in sustained attention or cognitive performance in neutral contexts more broadly. Evidence that amygdala functioning can impact sustained attention in nonemotional contexts can be found in animal studies suggesting that the amygdala serves as a general relevance detector (Gallagher & Holland, 1994; Holland, 2007; Holland & Gallagher, 1999; Holland, Han, & Gallagher, 2000; Sander, Grafman, & Zalla, 2003). Additionally, emerging literature in non‐ELT clinical populations suggests that amygdala functioning may interfere with sustained attention (Fleck et al., 2012).…”

A trip down memory lane about sex differences in the brain

“…Anatomical connections between the mPFC and the amygdala have been implicated in the mechanisms that mediate stress-related mental illnesses in humans as well as in traditional animal models of stress and learning [37,38,42]. To determine whether these anatomical connections were likewise necessary for the stress effects on learning, we conducted a classic disconnection study, similar to that developed by Holland [43]. The method is based on the fact that most (but not all) regions in the rodent brain are connected to one another only on one side of the brain.…”