Absence epileptic activity in Wistar Albino Glaxo Rijswijk rat mothers

Glial cells as mediators of protective actions of prolactin (PRL) in the CNS

Prolactin (PRL) is a hormone with multiple actions in the central nervous system (CNS) spanning from physiology to pathology. PRL exerts different actions through its receptors that can be found in both neurons and glial cells (astrocytes, microglia and oligodendrocytes) of the brain. Even though its effects during pregnancy and lactation, stress, anxiety, and depression are well studied, recent work on this hormone has brought to light a new role of PRL: that of a protective agent against brain damage and, consequently, against neurodegeneration. The mechanisms through which this protection takes place have not been fully elucidated; however, neurogenesis and anti-apoptosis are some of the plausible mechanisms that could mediate this effect. There is substantial information that implies the involvement of glial activation in this PRL effect, as shown in various models of brain damage. Taking into account glial cell dynamics and actions in various pathological conditions, combined with the neuroprotective effect of PRL, we consider of importance the revision of all the information about the interaction between these two cell types, as it will provide comprehensive knowledge about this new target of PRL against neuropathology.

Neonatal whisker trimming in WAG/Rij rat pups causes developmental delay, encourages maternal care and affects exploratory activity in adulthood

WAG/Rij rats are genetically predisposed to absence epilepsy. Maternal behavior in WAG/Rij female rats is known to differ from that in non-epileptic females. We hypothesize that (1) mother's behavior may be changed as response to changes in pup's conditions; (2) sensory deprivation at the neonatal age affect learning and behavior in adulthood. All whiskers in WAG/Rij rat pups were trimmed daily during PN1-PN8. Maternal behavior was examined during the same period. It was found that in the control group, WAG/Rij females often demonstrated abnormally long (>1 min) repetitive purposeless stereotypical actions that were roughly classified as compulsive-like behavior. Mothers of the trimmed pups showed less compulsive-like behavior and more intensively interacted with pups and built better nests. Rat pups in the trimmed group had lower body weight on PN7-PN19 as compared to the control. In the trimmed group, maturation of motor skills and early behavioral patterns (i.e. walking, grooming, vertical activity, motor functions of forelimbs) showed 1-2 days delay in comparison to the control. At the age of 2-2.5 months, the locomotor activity in the trimmed rats differed from the control, but the level of anxiety was the same (the open field and the elevated plus maze). At the age of 6 months, the trimmed and control rats showed no differences in conditioned avoidance learning test, therefore, neonatal whisker trimming did not influence fear-based learning abilities in adulthood. It is hypothesized that an enhanced maternal care is capable to modulate development of brain functions in sensory deprived progeny.