Why mother rats protect their children.

The presence of the hormone oxytocin in the central amygdala makes a mother rat willing to put her life in danger in order to protect her offspring.

The BTBR T+ tf/J mouse model for autism spectrum disorders-in search of biomarkers.

Autism spectrum disorders (ASD) form a common group of neurodevelopmental disorders appearing to be under polygenic control, but also strongly influenced by multiple environmental factors. The brain mechanisms responsible for ASD are not understood and animal models paralleling related emotional and cognitive impairments may prove helpful in unraveling them. BTBR T+ tf/J (BTBR) mice display behaviors consistent with the three diagnostic categories for ASD.

Absence of social conditioned place preference in BTBR T+tf/J mice: relevance for social motivation testing in rodent models of autism.

A major goal of translation research in autism is to characterize the physiological and psychological processes underlying behavioral abnormalities. Since autism reflects impairments in social motivation, we modified the mouse three-chamber social approach apparatus for use as a social conditioned place preference arena. We paired one of two unique contexts with social interactions in juvenile mice for five or ten conditioning sessions in BTBR T+tf/J mice and a control strain with normal approach behaviors (C57BL/6J) since the BTBR T+tf/J inbred mouse strain displays a variety of behavioral alterations analogous to symptoms of autism spectrum disorders.

Reduced sulfate plasma concentrations in the BTBR T+tf/J mouse model of autism.

Clinical studies have shown that children diagnosed with autism show abnormal sulfate chemistry, which is critical for cellular and metabolic processes. To determine if the inbred BTBR T+tf/J mouse shows autism-relevant aberrations in sulfate chemistry, the present study examined plasma sulfate concentrations in BTBR T+tf/J, inbred C57BL/6J, and outbred CD-1 mice. Results showed that the BTBR T+tf/J mouse exhibits significantly lower plasma sulfate concentrations in comparison to both C57BL/6J and CD-1 mice.

Fractone-associated N-sulfated heparan sulfate shows reduced quantity in BTBR T+tf/J mice: a strong model of autism.

BTBR T+tf/J (BTBR) mice show abnormal social, communicatory, and repetitive/stereotyped behaviors paralleling many of the symptoms of autism spectrum disorders. BTBR also show agenesis of the corpus callosum (CC) suggesting major perturbations of growth or guidance factors in the dorsal forebrain [1]. Heparan sulfate (HS) is a polysaccaride found in the brain and other animal tissues.

Age increases anxiety and reactivity of the fear/anxiety circuit in Lewis rats.

A growing body of data indicates that changes in emotional behavior occur with age. Young Lewis rats are known to display hypofunction of the HPA axis. With age the reactivity of this axis is thought to increase with a concomitant rise in anxiety.

BTBR T+tf/J mice: autism-relevant behaviors and reduced fractone-associated heparan sulfate.

BTBR T+tf/J (BTBR) mice have emerged as strong candidates to serve as models of a range of autism-relevant behaviors, showing deficiencies in social behaviors; reduced or unusual ultrasonic vocalizations in conspecific situations; and enhanced, repetitive self-grooming. Recent studies have described their behaviors in a seminatural visible burrow system (VBS); a Social Proximity Test in which avoidance of a conspecific is impossible; and in an object approach and investigation test evaluating attention to specific objects and potential stereotypies in the order of approaching/investigating objects. VBS results confirmed strong BTBR avoidance of conspecifics and in the Social Proximity Test, BTBR showed dramatic differences in several close-in behaviors, including specific avoidance of a nose-to-nose contact that may potentially be related to gaze-avoidance.

Diverse sensitivity of RHA/Verh and RLA/Verh rats to emotional and spatial aspects of a novel environment as a result of a distinct pattern of neuronal activation in the fear/anxiety circuit.

Psychogenetically selected Roman high (RHA/Verh) and Roman low (RLA/Verh) avoidance rats constitute a well-recognized model of diverse emotional reactivity. The two Swiss lines display marked behavioral and endocrine differences in reaction to a novel environment. In our study we found that these differences are accompanied by a distinct, line-specific pattern of neuronal activation within the fear/anxiety circuit.

The effect of age on the dynamics and the level of c-Fos activation in response to acute restraint in Lewis rats.

Recent studies have reported an age-related increase of anxiety in rodents with a concomitant decrease in neuronal activity in some of the key structures of the fear/anxiety circuit. In the present study we present evidence that distinct parts of this circuit are differentially affected by age in Lewis rats. The effect of ageing is observed both at the actual level of neuronal activation and its time-course.

Photoperiod affects distribution of dynorphin A in the brain of Siberian hamster.

Dynorphin A1-77 (DYN A1-17) acting in the CNS is known to affect thermoregulation, water and energy balance in the short time scale. In this study a long-term alteration of these functions induced by changes of day length in the highly photoperiodic species, the Siberian hamster (Phodopus sungorus) was studied using immunohistochemistry for DYN A1-17. We found that in the long day (LD, L:D 16 h:8 h) more brain areas express DYN A1-17 peptide than in the short day (SD, L:D 8 h:16 h) conditions.