When is the rat retrosplenial cortex required for stimulus integration?
The rodent retrosplenial cortex is known to be vital for spatial cognition, but evidence has also pointed to a role in processing nonspatial information. It has been suggested that the retrosplenial cortex may serve as a site of integration of incoming sensory information. To examine this proposal, the current set of experiments assessed the impact of excitotoxic lesions in the retrosplenial cortex on two behavioral tasks that tax animals’ ability to process multiple and overlapping environmental stimuli. In Experiment 1, rats with retrosplenial lesions acquired a negative patterning discrimination, a form of configural ...
Source: Behavioral Neuroscience - October 15, 2018 Category: Neuroscience Source Type: research
Converging meta-analytic and connectomic evidence for functional subregions within the human retrosplenial region.
This study combines two large databases to provide a novel methodological blueprint for understanding brain function in the RS region and beyond. (PsycINFO Database Record (c) 2018 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - October 15, 2018 Category: Neuroscience Source Type: research
Introduction to the special issue on the cognitive functions of the retrosplenial cortex.
This special issue on the cognitive functions of the retrosplenial cortex highlights progress that has been made in recent years in understanding the anatomy and function of the retrosplenial cortex in both animals and humans. The articles in this issue of Behavioral Neuroscience use a number of different approaches that together provide an up-to-date account of recent progress in understanding how the retrosplenial cortex contributes to cognition, with an emphasis on its functional role in spatial navigation and learning and memory. (PsycINFO Database Record (c) 2018 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - October 15, 2018 Category: Neuroscience Source Type: research
Sensorimotor representation and functional motor changes following short-term arm immobilization.
Limb immobilization paradigms are increasingly used to investigate changes in brain plasticity and support potential rehabilitation techniques that might help counteract motor impairments. Yet, it remains unclear how unilateral arm immobilization may influence the sensorimotor representation and functional output for both arms. Using a randomized crossover design, 14 participants underwent a baseline test, followed by two experimental conditions separated by 1 week: a right (dominant) arm immobilization phase over a period of 8 hr and a no-immobilization (or control) phase also lasting 8 hr. Before and after each condition...
Source: Behavioral Neuroscience - October 8, 2018 Category: Neuroscience Source Type: research
“Fast” versus “slow” word integration of visual and olfactory objects: EEG biomarkers of decision speed variability.
In psychological experiments, behavioral speed varies across trials, and this variation is often associated with corresponding fluctuations in cortical activity. Little is known about such cortical variations in semantic priming tasks where target words are matched with preceding sensory object cues. Here, two visually presented target words (“pear” and “lilac”) were repeatedly cued by corresponding odors or pictures, and the participants were to indicate matching or nonmatching combinations. Data were split in behaviorally “fast” versus “slow” trials. We hypothesized that slow trials would be associated wi...
Source: Behavioral Neuroscience - October 8, 2018 Category: Neuroscience Source Type: research
Blockade of dopamine D₁ receptors, but not D₂ receptors, decreases motivation in a novel effort-discounting paradigm in common marmosets.
Effort-based decision-making paradigms have recently been used to measure motivation in healthy subjects and patients with neuropsychiatric disorders. In the present study, we developed a novel effort-discounting paradigm using a touch-panel system in common marmosets. Marmosets were trained to choose between a low-reward (a piece of cake) requiring low-effort (one touch response) versus high-reward (three pieces of cake) requiring one of three different effort levels (one, two, or four touch responses). Because the number of trials per session was kept constant, the selection of the high-reward choice was always the optim...
Source: Behavioral Neuroscience - October 8, 2018 Category: Neuroscience Source Type: research
Reversal learning impairments in the maternal immune activation rat model of schizophrenia.
One of the cognitive symptoms observed in schizophrenia is decreased flexibility in several tasks, including reversal learning. Reversal learning has previously been tested in rats following maternal immune activation (MIA), a risk factor for schizophrenia, with varying results. Whereas some previous studies have shown that MIA rats are slower to learn a reversal, others have reported more rapid learning compared with controls. Several of these latter studies have, however, used a T-maze task with aversive, negative reinforcement as a motivating factor. Because most human studies use positive reinforcement in reversal task...
Source: Behavioral Neuroscience - October 8, 2018 Category: Neuroscience Source Type: research
Context-dependent reinstatement of an extinguished operant response in preweanling rats.
It is frequently assumed that infants are impaired in contextual memory and consequently, in recovery from extinction, a phenomenon considered to be context dependent. However, the evidence in the field is far from consistent with this interpretation, since several studies have shown context-dependent extinction in infant rats using a variety of procedures and behavioral measures. This discussion has primarily been based on studies using Pavlovian conditioning tasks. Three experiments were conducted to study reinstatement of an extinguished operant response and additionally to evaluate the context dependence of such an eff...
Source: Behavioral Neuroscience - October 8, 2018 Category: Neuroscience Source Type: research
Pain chronification and chronic pain impair a defensive behavior, but not the ability of acute pain to facilitate it, through the activation of an endogenous analgesia circuit.
The endogenous ability to decrease pain perception during life-threatening situations is crucial to the prevention of recuperative behaviors and to leave the subject free to engage in appropriated defensive responses. We have previously shown that acute pain activates the ascending nociceptive control—an endogenous analgesia circuit dependent on opioid mechanisms within nucleus accumbens—to facilitate the tonic immobility response, an innate defensive behavior. Now we asked whether chronic pain and pain chronification impairs either the tonic immobility response or the ability of acute pain to facilitate it by activati...
Source: Behavioral Neuroscience - October 4, 2018 Category: Neuroscience Source Type: research
Emotion-modulated startle reflex during reappraisal: Probe timing and behavioral correlates.
We presented negative and neutral pictures to N = 47 participants. Pictures were paired with the instruction to reappraise or to maintain the emotions elicited by these pictures. Probes were delivered at three different times during a 12.5-s regulation phase, and the startle response was measured with electromyography. Valence and arousal ratings were assessed after each trial. Results revealed no significant impact of probe time on startle inhibition during reappraisal. Startle inhibition and perceived down-regulation of arousal were significantly and positively correlated, whereas perceived down-regulation of valence was...
Source: Behavioral Neuroscience - October 4, 2018 Category: Neuroscience Source Type: research
Rapid effects of sex steroids on zebra finch (Taeniopygia guttata) pair maintenance.
Although steroids are widely known to affect behavior through activation of nuclear/cytosolic receptors (“genomic” effects), steroids can also rapidly affect behavior via modulation of signal transduction pathways (“nongenomic,” fast actions, or rapid effects). In zebra finches, there is evidence that sex steroids have context-specific effects on pair-maintenance behavior, on both acute and chronic timescales. Here, we quantified the effects of orally administered testosterone and 17β-estradiol (E2) on pair-maintenance behavior. We show that E2 rapidly affects female, but not male, affiliative behavior profiles du...
Source: Behavioral Neuroscience - October 4, 2018 Category: Neuroscience Source Type: research
Poststroke exercise is as effective as skilled rehabilitation: Effects in young and aged mice.
Stroke is a leading cause of long-term disability, though current rehabilitative strategies fail to yield complete recovery. Focused training of the impaired limb improves functional outcome in rodents, but these strategies require intensive training that is difficult to practice in humans. Because aerobic exercise has been found to induce beneficial changes in the brain, it is a promising rehabilitative strategy after stroke. The current study investigated the effect of voluntary poststroke aerobic exercise on functional outcome in young and aged mice. Mice were trained on a skilled reaching task before receiving focal is...
Source: Behavioral Neuroscience - September 27, 2018 Category: Neuroscience Source Type: research
Acetaminophen disrupts memory in object recognition and increases extracellular signal-regulated kinase phosphorylation in male mice.
Acetaminophen (also known as paracetamol) is a commonly used over-the-counter pain medication, but recent evidence suggests that a single exposure or prenatal exposure may have significant behavioral effects. This investigation aimed to determine whether acetaminophen could disrupt memory formation in an object-recognition task and to quantify potential changes in memory-related signaling cascades in the hippocampus of mice after acetaminophen administration. Using male mice, we examined the effect of a single subcutaneous injection of acetaminophen on the object-recognition task, a single-trial, hippocampus-dependent memo...
Source: Behavioral Neuroscience - August 30, 2018 Category: Neuroscience Source Type: research
Lasting impact on memory of midlife exposure to exogenous and endogenous estrogens.
We previously demonstrated that 40 days of prior midlife estradiol treatment results in enhanced spatial memory in aging ovariectomized rats long after termination of the estradiol treatment. Our current goal was to determine whether this benefit is due to lasting impacts on memory specifically of previous exogenous estradiol treatment or simply due to delaying cognitive deficits that occur following loss of ovarian hormones. Middle-aged rats were ovariectomized or underwent sham surgery. Ovariectomized rats received estradiol (Previous Estradiol) or vehicle (Previous Vehicle) implants. Rats undergoing sham surgery (Previo...
Source: Behavioral Neuroscience - August 30, 2018 Category: Neuroscience Source Type: research
Heterogeneity in human retrosplenial cortex: A review of function and connectivity.
Retrosplenial cortex (RSC) is an important information hub in the brain and several mental disorders demonstrate RSC dysfunction, but its role is still largely unclear. Although researchers in many cognitive domains have recognized the importance of RSC, a broader synthesis of RSC function across cognitive domains is lacking. This review examines human RSC function across several cognitive domains, considering both specific cognitive functions and the RSC subregions in which that function occurs. Overall, this review found evidence for a functional gradient across the anterior-posterior axis of RSC involving several cognit...
Source: Behavioral Neuroscience - August 30, 2018 Category: Neuroscience Source Type: research
