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It has been shown that the gradual increase in the intensity of electrical stimulation of the dorsal periaqueductal gray (DPAG), deep layers of the superior colliculus (DLSC) and inferior colliculus of rats induces, in a progressive manner, characteristic aversive responses such as arousal, freezing, and escape behavior. The DPAG-DLSC together with the(More)
The aim of this study was to examine the state of anxiety and the 17beta-estradiol and progesterone levels in rats tested in the elevated plus-maze during the four phases of the estrous cycle. Male rats, female rats during each of the four phases of the estrous cycle, ovariectomized rats, and diestrus female rats treated with estradiol were tested in the(More)
The inferior colliculus (IC) is a well known relay station for auditory pathways in the brainstem. In the present review we are suggesting that aversive states are also generated and elaborated in the inferior colliculus and that this structure may be part of a brain system commanding defensive behavior. The evidences presented in this review have been(More)
It has been suggested that access to high caloric food attenuates stress response. The present paper investigates whether access to commercial chow enriched with glucose and fat, here referred to as comfort food alters behavioral, metabolic, and hormonal parameters of rats submitted to three daily sessions of foot-shock stress. Food intake, anxiety-like(More)
Electrical or chemical stimulation of the inferior colliculus (IC) induces fear-like behaviors. More recently, consistent evidence has shown that electrical stimulation of the central nucleus of the IC supports Pavlovian conditioning and latent inhibition (LI). LI is characterized by retardation in conditioning and also by an impaired ability to ignore(More)
In addition to being a relay station for auditory pathways in the brainstem, the inferior colliculus may also be part of a brain system commanding defensive behavior. In the present work, we present evidence for the serotonergic modulation of the neural substrate of aversion in this structure. Rats implanted with an electrode-cannula in the inferior(More)
In the present work, evidence is presented for the involvement of inferior colliculus in the generation and elaboration of aversive responses which suggests that this structure may be part of a brain system that commands aversive states. Electrical stimulation of the inferior colliculus of rats placed inside an open field allowed the determination of(More)
The inferior colliculus has been implicated in aversive or anxiogenic aspects of defensive behavior. Animals learn to turn off electrical stimulation applied to the inferior colliculus. The purpose of the present study was to determine (1) whether this aversion induced by electrical stimulation can be conditioned to a conditioned stimulus (CS, light) and(More)
Deep layers of the superior colliculus, the dorsal periaqueductal gray matter and the inferior colliculus are midbrain structures involved in the generation of defensive behavior and fear-induced anti-nociception. Local injections of the GABA(A) antagonist bicuculline into these structures have been used to produce this defense reaction. Serotonin is(More)
Drugs and neurotoxins activate specific neural circuits by increasing or decreasing the formation and release of neurotransmitters, such as nitric oxide (NO), and by inducing immediate early genes, such as FOS. We have previously shown that Phoneutria nigriventer spider venom (PNV) impairs the microtubule-dependent transcellular barrier of the blood-brain(More)