Roger A. Kroes

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Rats (Rattus norvegicus) emit a variety of ultrasonic vocalizations throughout their lifespan that reflect different forms of emotional arousal and accompanying affective states. In this study, high frequency recordings of ultrasonic vocalizations were made during mating, aggression, and both conspecific and heterospecific (dubbed "tickling")(More)
Fifty-kHz ultrasonic vocalizations have been proposed to reflect a positive appetitive affective state in rats, being consistently linked to the positive appetitive behavior. In the first study, we examined the brain substrates of 50-kHz ultrasonic vocalizations (USVs) by using localized electrical stimulation of the brain (ESB) at various sites that are(More)
Recent human clinical studies with the NMDA receptor (NMDAR) antagonist ketamine have revealed profound and long-lasting antidepressant effects with rapid onset in several clinical trials, but antidepressant effects were preceded by dissociative side effects. Here we show that GLYX-13, a novel NMDAR glycine-site functional partial agonist, produces an(More)
Gene expression profiles in the cortex of adult Long-Evans rats as a function of a stressful social loss and victory in inter-male fighting encounters were examined. This social dominance and subordination model has been postulated to simulate early changes in the onset of depression in the losers. Microarrays were fabricated containing 45mer(More)
Positive emotional states have been shown to confer resilience to depression and anxiety in humans, but the molecular mechanisms underlying these effects have not yet been elucidated. In laboratory rats, positive emotional states can be measured by 50-kHz ultrasonic vocalizations (hedonic USVs), which are maximally elicited by juvenile rough-and-tumble play(More)
Effects of direct injections of amphetamine into the shell of the nucleus accumbens were studied in three lines of Long-Evans rats, two of which had been selected for low and high rates of 50 kHz calls in adolescence in response to a standard social stimulation, and compared to results from randomly selected rats. Injections of amphetamine into the medial(More)
Rapastinel (GLYX-13) is an N-methyl-d-aspartate receptor (NMDAR) modulator that has characteristics of a glycine site partial agonist. Rapastinel is a robust cognitive enhancer and facilitates hippocampal long-term potentiation (LTP) of synaptic transmission in slices. In human clinical trials, rapastinel has been shown to produce marked antidepressant(More)
Fifty-kHz ultrasonic vocalizations have previously been shown to be positively correlated with reward and appetitive social behavior in rats, and to reflect a positive affective state. In this study, rats selectively bred for high and low rates of 50-kHz vocalizations as juveniles were tested as adults in a battery of behavioral tests for social/emotional(More)
Sodium salicylate, an anti-inflammatory agent, was examined for its effects on the heat shock response in cultured human cells. Salicylate activation of DNA binding by the heat shock transcription factor (HSF) was comparable to activation attained during heat shock. However, sodium salicylate did not induce heat shock gene transcription even though the HSF(More)
INTRODUCTION The N-methyl-d-aspartate receptor-ionophore complex plays a key role in learning and memory and has efficacy in animals and humans with affective disorders. GLYX-13 is an N-methyl-d-aspartate receptor (NMDAR) glycine-site functional partial agonist and cognitive enhancer that also shows rapid antidepressant activity without psychotomimetic side(More)