Negative attributes of mixed-valence memories strengthen over long retention intervals and the degree of enhancement is predicted by individual differences in state anxiety.
Behavioral Neuroscience, Vol 137(6), Dec 2023, 380-391; doi:10.1037/bne0000575Memories are multifaceted and can simultaneously contain positive and negative attributes. Here, we report that negative attributes of a mixed-valence memory dominate long-term recall. To induce a mixed-valence memory, running responses were randomly reinforced with either food (∼83% of trials) or footshock (∼17% of trials), or a noise conditioned stimulus (CS) was followed randomly with either food (∼80% of trials) or footshock (∼20% of trials). Control animals were consistently reinforced with only food. Mixed-valence training promoted ...
Source: Behavioral Neuroscience - October 30, 2023 Category: Neuroscience Source Type: research
Are reactions to frustrative nonreward in other animals a model for human anger? Neurobehavioral implications and therapeutic applications.
Behavioral Neuroscience, Vol 137(6), Dec 2023, 364-372; doi:10.1037/bne0000574Anger is a powerful and mostly deleterious emotion that can impair an individual’s health and social relationships and that imposes considerable costs on society at large. It is a constituent of multiple psychopathologies, most notably intermittent explosive disorder. Excessive anger can drive injurious and even lethal reactive aggression. To understand its biobehavioral origins and develop appropriate therapeutic interventions, an animal model of human anger would be quite useful. The phenomena of aggression provoked by frustrative nonreward (...
Source: Behavioral Neuroscience - October 30, 2023 Category: Neuroscience Source Type: research
Retrieval and savings of contextual fear memories across an extended retention interval in juvenile and adult male and female rats.
Behavioral Neuroscience, Vol 137(6), Dec 2023, 339-346; doi:10.1037/bne0000569Adult rodents exhibit an exceptional ability to retrieve context fear memories across lengthy retention intervals. In contrast, these memories established in younger rodents are susceptible to significant forgetting. The present study aimed to examine the persistence of contextual fear memories established in juvenile and adult Long-Evans male and female rats. Testing 1-day after conditioning, adult males exhibited evidence for greater conditioning than juvenile males, while in females, conditioning did not differ between juvenile and adult rats....
Source: Behavioral Neuroscience - October 30, 2023 Category: Neuroscience Source Type: research
Prelimbic cortex inactivation prevents ABA renewal based on stress state.
Behavioral Neuroscience, Vol 137(6), Dec 2023, 373-379; doi:10.1037/bne0000570Our recent research suggests that the interoceptive state associated with stress can function as a contextual stimulus for operant behavior. In the present experiment, we investigated the role of the rodent prelimbic cortex (PL), a brain region that is critical in contextual control of operant behavior, in the ability of a stressed state to produce ABA renewal of an extinguished operant response. Rats were trained to perform a lever press response for a food pellet reward during daily sessions that followed exposure to a stressor that changed eac...
Source: Behavioral Neuroscience - October 12, 2023 Category: Neuroscience Source Type: research
Optogenetic inhibition of the caudal substantia nigra inflates behavioral responding to uncertain threat and safety.
Behavioral Neuroscience, Vol 137(6), Dec 2023, 347-355; doi:10.1037/bne0000568Defensive responding is adaptive when it approximates the current threat but maladaptive when it exceeds the current threat. Here we asked if the substantia nigra, a region consistently implicated in reward, is necessary to show appropriate levels of defensive responding in Pavlovian fear discrimination. Rats received bilateral transduction of the caudal substantia nigra with halorhodopsin or a control fluorophore and bilateral ferrule implants. Rats then behaviorally discriminated cues predicting unique foot shock probabilities (danger, p = 1; u...
Source: Behavioral Neuroscience - October 5, 2023 Category: Neuroscience Source Type: research
Hippocampal and amygdala volumes vary with residential proximity to toxicants at Birmingham, Alabama’s 35th Avenue Superfund site.
Behavioral Neuroscience, Vol 137(5), Oct 2023, 330-338; doi:10.1037/bne0000564Exposure to environmental toxicants have serious implications for the general health and well-being of children, particularly during pivotal neurodevelopmental stages. The Environmental Protection Agency’s (EPA) Superfund program has identified several areas (Superfund sites) across the United States with high levels of environmental toxicants, which affect the health of many residents in nearby communities. Exposure to these environmental toxicants has been linked to changes in the structure and function of the brain. However, limited research...
Source: Behavioral Neuroscience - July 20, 2023 Category: Neuroscience Source Type: research
Mental representations mediate aversive learning in humans.
Behavioral Neuroscience, Vol 137(5), Oct 2023, 319-329; doi:10.1037/bne0000565Mental representations of stimuli that are not physically present are critical for a range of cognitive capacities, including perception, memory, and learning. Overly robust mental representations, however, can contribute to hallucinations in healthy individuals and those diagnosed with psychotic illness. Measuring the strength of mental representations can thus provide insight into how the contents of the mind influence both adaptive and maladaptive behaviors. In rodents, the robustness of mental representations has been tested using the represe...
Source: Behavioral Neuroscience - July 6, 2023 Category: Neuroscience Source Type: research
Proteome analysis indicates participation of the dorsal hippocampal formation in fear-motivated memory in a time-dependent manner.
Behavioral Neuroscience, Vol 137(5), Oct 2023, 303-318; doi:10.1037/bne0000563Our previous behavioral and molecular data indicate a central role of the dorsal hippocampal formation (dHF) in recent conditioned lick suppression memory. The purpose of this study was to investigate the role of the dHF in recent and remote memory of conditioned lick suppression employing proteomic analysis. Two or 40 days after conditioning, the rats were subjected to a retention test and were then euthanized after 24 hr for dHF collection. We identified 1,165 proteins and quantified 265 proteins. Upregulation of five proteins and downregulatio...
Source: Behavioral Neuroscience - July 6, 2023 Category: Neuroscience Source Type: research
Distinct competitive impacts of palatability of taste stimuli on sampling dynamics during a preference test.
Behavioral Neuroscience, Vol 137(5), Oct 2023, 289-302; doi:10.1037/bne0000562Food or taste preference tests are analogous to naturalistic decisions in which the animal selects which stimuli to sample and for how long to sample them. The data acquired in such tests, the relative amounts of the alternative stimuli that are sampled and consumed, indicate the preference for each. While such preferences are typically recorded as a single quantity, an analysis of the ongoing sampling dynamics producing the preference can reveal otherwise hidden aspects of the decision-making process that depend on its underlying neural circuit ...
Source: Behavioral Neuroscience - June 29, 2023 Category: Neuroscience Source Type: research
Muscimol inactivation of dorsal striatum in young and aged male rats does not affect paired associates learning performance.
This study found that inactivation of the DS did not alter PAL performance in young or aged rats, but did alter a positive control, DS-dependent spatial navigation task. This observation suggests that elevated DS activity does not play a role in the decline of HPC-dependent PAL performance in aged male rats. Given the persistent tendencies of aged rodents toward DS-dependent learning, it will be worthwhile to explore further the coordination dynamics between the HPC and DS that may contribute to age-related cognitive decline. (PsycInfo Database Record (c) 2023 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - June 15, 2023 Category: Neuroscience Source Type: research
A single dose of ketamine enhances early life stress-induced aggression with no effect on fear memory, anxiety-like behavior, or depression-like behavior in mice.
Behavioral Neuroscience, Vol 137(5), Oct 2023, 281-288; doi:10.1037/bne0000560Ketamine is a dissociative anesthetic that has been shown to have antidepressant effects in humans and has been proposed as a potential treatment for mood disorders such as posttraumatic stress disorder and aggression. However, previous studies from our lab and others have demonstrated that ketamine’s effects are highly context- and dose-dependent. In a recent study, we found that 10 mg/kg ketamine could exacerbate the effects of early life stress on excessive aggression in mice. To further investigate, the effect of ketamine on moods, such as ...
Source: Behavioral Neuroscience - June 15, 2023 Category: Neuroscience Source Type: research
The motivational role of the ventral striatum and amygdala in learning from gains and losses.
Behavioral Neuroscience, Vol 137(4), Aug 2023, 268-280; doi:10.1037/bne0000558The ventral striatum (VS) and amygdala are two structures often implicated as essential structures for learning. The literature addressing the contribution of these areas to learning, however, is not entirely consistent. We propose that these inconsistencies are due to learning environments and the effect they have on motivation. To differentiate aspects of learning from environmental factors that affect motivation, we ran a series of experiments with varying task factors. We compared monkeys (Macaca mulatta) with VS lesions, amygdala lesions, an...
Source: Behavioral Neuroscience - May 4, 2023 Category: Neuroscience Source Type: research
Ketamine facilitates appetitive trace conditioning in mice: Further evidence for abnormal stimulus representation in schizophrenia model animals.
Behavioral Neuroscience, Vol 137(4), Aug 2023, 236-253; doi:10.1037/bne0000559Recent studies indicated that positive symptoms of schizophrenia, such as hallucination and delusion, can be modeled using Pavlovian conditioning procedures. Various schizophrenia model animals exhibit abnormally strong associative activations of absent stimuli (i.e., conditioned hallucination) and readily form further associations involving the absent cues (i.e., enhanced mediated conditioning). In the present study using mice, we examined whether the acquisition of appetitive trace conditioning, another Pavlovian task in which animals must form...
Source: Behavioral Neuroscience - May 1, 2023 Category: Neuroscience Source Type: research
Divergent risky decision-making and impulsivity behaviors in Lewis rat substrains with low genetic difference.
In conclusion, Lewis rat substrains differ significantly in risk-taking and impulsivity and only a small number of easily mapped variants are likely to be causal. Sequencing combined with a reduced complexity cross should enable identification of one or more variants underlying multiple complex addiction-relevant behaviors. (PsycInfo Database Record (c) 2023 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - April 27, 2023 Category: Neuroscience Source Type: research
Prefrontal and medial temporal interactions in memory functions in the rhesus monkey.
Behavioral Neuroscience, Vol 137(3), Jun 2023, 211-222; doi:10.1037/bne0000556Both the medial temporal lobe and the dorsolateral prefrontal cortex have been implicated in learning and memory. However, it has been difficult to ascertain the degree to which the two structures are dependent on each other or interact in subserving these cognitive functions. To investigate this question directly, we prepared two group of monkeys. First, the contralateral frontal-hippocampal split group (CFHS) received a unilateral lesion of the hippocampus and surrounding posterior parahippocampal cortices (H +), combined with a contralateral l...
Source: Behavioral Neuroscience - April 6, 2023 Category: Neuroscience Source Type: research
