MEMRI for visualizing brain activity after auditory stimulation in frogs.
Anuran amphibians are common model organisms in bioacoustics and neurobiology. To date, however, most available methods for studying auditory processing in frogs are highly invasive and thus do not allow for longitudinal study designs, nor do they provide a global view of the brain, which substantially limits the questions that can be addressed. The goal of this study was to identify areas in the frog brain that are responsible for auditory processing using in vivo manganese-enhanced MRI (MEMRI). We were interested in determining if the neural processing of socially relevant acoustic stimuli (e.g., species-specific calls) ...
Source: Behavioral Neuroscience - May 2, 2019 Category: Neuroscience Source Type: research
Auditory communication processing in bats: What we know and where to go.
Bats are the second largest mammalian order, with over 1,300 species. These animals show diverse behaviors, diets, and habitats. Most bats produce ultrasonic vocalizations and perceive their environment by processing information carried by returning echoes of their calls. Echolocation is achieved through a sophisticated audio-vocal system that allows bats to emit and detect frequencies that can range from ten to hundreds of kilohertz. In addition, most bat species are gregarious, and produce social communication calls that vary in complexity, form, and function across species. In this article, we (a) highlight the value of...
Source: Behavioral Neuroscience - May 2, 2019 Category: Neuroscience Source Type: research
Behavioral and neural aspects of the spatial processing of conspecifics signals in the electrosensory system.
Localizing the source of a signal is often as important as deciphering the signal’s message. Localization mechanisms must cope with the challenges of representing the spatial information of weak, noisy signals. Comparing these strategies across modalities and model systems allows a broader understanding of the general principles shaping spatial processing. In this review we focus on the electrosensory system of knifefish and provide an overview of our current understanding of spatial processing in this system, in particular, localization of conspecific signals. We argue that many mechanisms observed in other sensory syst...
Source: Behavioral Neuroscience - May 2, 2019 Category: Neuroscience Source Type: research
Echolocating bats perceive natural-size targets as a unitary class using micro-spectral ripples in echoes.
Echolocating big brown bats emit frequency-modulated (FM) sounds covering ultrasonic frequencies in two harmonic sweeps (FM1 from 50–60 kHz sweeping down to 20–25 kHz, FM2 from 100–110 kHz sweeping down to 45 kHz). Using a complex interplay of acoustic cues, the bats perceive object distance from echo delay and object shape from echo spectra. Typical natural targets—flying insects—return discrete reflections, called glints, from prominent body parts (e.g., head, wings). Insect sizes are mostly 0.5 cm to about 3.5 cm, corresponding to reflected time separations of 30 to 210 μs. When closely spaced reflections ove...
Source: Behavioral Neuroscience - April 25, 2019 Category: Neuroscience Source Type: research
Limited capabilities for condition-dependent modulation of vocal turn-taking behavior in marmoset monkeys.
Taking turns plays an important role in primate communication and involves individuals producing species-specific calls in response to conspecific vocalizations. Recent studies have revealed that marmoset monkeys are an ideal primate model system to investigate vocal turn-taking behavior and the corresponding sensory-motor interactions. However, it is largely unknown how external factors such as conspecific call latency influence this vocal behavior. Using interactive playback, we systematically answered vocalizations of monkeys with either short- or long-call response latencies. By placing marmosets in these different beh...
Source: Behavioral Neuroscience - April 22, 2019 Category: Neuroscience Source Type: research
Understanding cerebellum in vertebrate neuroethology: From sensing in sharks and electric fish to motor sequences in movement and birdsong.
The elaborate structure of the cerebellum has been long known, although its contribution to a remarkable diversity of behavior is only recently appreciated. Taking an evolutionary perspective, we consider the wider function of the cerebellum based on insight from the function of so-called cerebellum-like structures. Cerebellum-like structures cancel the effects of self-stimulation, a function that has been well characterized in both elasmobranch and weakly electric fish. This function depends on the implementation of an adaptive filter, which provides an input-output transformation modified by specific learning rules. We a...
Source: Behavioral Neuroscience - April 22, 2019 Category: Neuroscience Source Type: research
Upregulation of hippocampal extracellular signal-regulated kinase (ERK)–2 induces antidepressant-like behavior in the rat forced swim test.
The hippocampus mediates responses to affect-related behavior in preclinical models of pharmacological antidepressant efficacy, such as the forced swim test. However, the molecular mechanisms that regulate escape-directed behavior in this preclinical model of despair are not well understood. Here, using viral-mediated gene transfer, we assessed how overexpression of extracellular signal-regulated protein kinase (ERK)–2 within the dorsal hippocampus influenced behavioral reactivity to inescapable swimming stress in adult male Sprague–Dawley rats. When compared to controls, rats overexpressing hippocampal ERK-2 displayed...
Source: Behavioral Neuroscience - March 25, 2019 Category: Neuroscience Source Type: research
Amygdala and prefrontal cortex activity varies with individual differences in the emotional response to psychosocial stress.
Stress elicits a variety of psychophysiological responses that show large interindividual variability. Determining the neural mechanisms that mediate individual differences in the emotional response to stress would provide new insight that would have important implications for understanding stress-related disorders. Therefore, the present study examined individual differences in the relationship between brain activity and the emotional response to stress. In the largest stress study to date, 239 participants completed the Montreal Imaging Stress Task (MIST) while heart rate, skin conductance response (SCR), cortisol, self-...
Source: Behavioral Neuroscience - March 25, 2019 Category: Neuroscience Source Type: research
Involvement of lactate transport in two object recognition tasks that require either the hippocampus or striatum.
This study evaluated the selective involvement of hippocampal and striatal lactate in two object recognition tasks. The tasks tested recognition memory after a change in location of two target objects (double object location; dOL) or after replacement of familiar targets with two new objects set in the original locations (double object replacement; dOR). Rats received three study sessions across which exploration times decreased. The recognition index was the change in exploration time of both objects on a test trial from the exploration times on the final study trial. We first verified a double dissociation between hippoc...
Source: Behavioral Neuroscience - March 25, 2019 Category: Neuroscience Source Type: research
Occasion setting.
Occasion setting refers to the ability of 1 stimulus, an occasion setter, to modulate the efficacy of the association between another, conditioned stimulus (CS) and an unconditioned stimulus (US) or reinforcer. Occasion setters and simple CSs are readily distinguished. For example, occasion setters are relatively immune to extinction and counterconditioning, and their combination and transfer functions differ substantially from those of simple CSs. Similarly, the acquisition of occasion setting is favored when stimuli are separated by longer intervals, by empty trace intervals, and are of different modalities, whereas the ...
Source: Behavioral Neuroscience - March 25, 2019 Category: Neuroscience Source Type: research
Immediate and long-lasting cognitive consequences of adolescent chronic sleep restriction.
This study is the first rodent model to use a longitudinal approach to investigate adolescent CSR and provides practical implications for the health of adolescents. (PsycINFO Database Record (c) 2019 APA, all rights reserved) (Source: Behavioral Neuroscience)
Source: Behavioral Neuroscience - March 21, 2019 Category: Neuroscience Source Type: research
Repetitive mild concussion in subjects with a vulnerable cholinergic system: Lasting cholinergic-attentional impairments in CHT+/− mice.
Previous research emphasized the impact of traumatic brain injury on cholinergic systems and associated cognitive functions. Here we addressed the converse question: Because of the available evidence indicating cognitive and neuronal vulnerabilities in humans expressing low-capacity cholinergic systems or with declining cholinergic systems, do injuries cause more severe cognitive decline in such subjects, and what cholinergic mechanisms contribute to such vulnerability? Using mice heterozygous for the choline transporter (CHT+/− mice) as a model for a limited cholinergic capacity, we investigated the cognitive and neuron...
Source: Behavioral Neuroscience - March 21, 2019 Category: Neuroscience Source Type: research
Inactivation of the interpositus nucleus during unpaired extinction does not prevent extinction of conditioned eyeblink responses or conditioning-specific reflex modification.
For almost 75 years, classical eyeblink conditioning has been an invaluable tool for assessing associative learning processes across many species, thanks to its high translatability and well-defined neural circuitry. Our laboratory has adapted the paradigm to extensively detail associative changes in the rabbit reflexive eyeblink response (unconditioned response, UR), characterized by postconditioning increases in the frequency, size, and latency of the UR when the periorbital shock unconditioned stimulus (US) is presented alone, termed conditioning-specific reflex modification (CRM). Because the shape and timing of CRM cl...
Source: Behavioral Neuroscience - March 14, 2019 Category: Neuroscience Source Type: research
Sex experience increases delta FosB in male and female hamsters, but facilitates sex behavior only in females.
Motivated behaviors share the common feature of activating the mesolimbic dopamine system. Repeated experience with motivated behaviors can cause long-lasting structural changes in the nucleus accumbens (NAc). The molecular mechanisms underlying this experience-dependent plasticity in the NAc have been well described following experience with drugs of abuse. In particular, the transcription factor Delta FosB (ΔFosB) is a key regulator of drug-related neuroplasticity. Fewer studies have examined the molecular mechanisms underlying experience-dependent plasticity in the NAc following naturally motivated behaviors, but previ...
Source: Behavioral Neuroscience - March 14, 2019 Category: Neuroscience Source Type: research
Effects of nicotine exposure and anxiety on motivation for reward and gambling-like cues under reward uncertainty.
Reward uncertainty is a common characteristic of gambling and may powerfully enhance attraction to gambling-related cues, thus promoting maladaptive gambling behaviors in susceptible individuals. The co-occurrence of gambling disorder with tobacco use disorder (60.4%) suggests a common mechanism for their pathology, and comorbid anxiety (41.3%) might further promote the maintenance of these behaviors. However, it is unknown how nicotine or anxiety might contribute to cue and reward attraction, or promote disordered gambling behavior. In the present study, we investigated the effects of nicotine (0.4 mg/kg, SC) on the desir...
Source: Behavioral Neuroscience - March 14, 2019 Category: Neuroscience Source Type: research
