04/11/2009

CASE STUDY: se a coisa é assim no Octodon degus, imagine-se no homo sapiens


Dad Matters, Too! Paternal Deprivation Delays/Suppresses Dendritic and Synaptic Development in the Orbitofrontal and Somatosensory Cortex

«Research indicates that paternal care is essential for the development of limbic brain regions, i.e., a brain system, which mediates emotional behaviors as well as learning and memory formation. Comparing the brains of male degus (Octodon degus, or “trumpet tailed” rat, a biparental rodent) raised by both parents with those that had been raised by a single mother revealed that paternal deprivation results in delayed or suppressed cortical dendritic and synaptic growth and reorganization.

Modern societies are increasingly concerned that fatherless children are at dramatically greater risk of drug and alcohol abuse, poor educational performance, and criminality. Since the establishment of functional neuronal networks in the brain of animals, including humans, is essentially sculpted by childhood experience (emotional and cognitive), the impaired behavioral development observed in fatherless children may be caused by the lack of paternal input, resulting in delayed brain development and even permanently retarded brain function.

In order to test this hypothesis, the researchers raised newborn degus either in single-mother families or in families, where both parents took care of their pups. In support of our hypothesis, we found significantly reduced densities of excitatory spine synapses in the orbitofrontal (limbic) and somatosensory (i.e., touch, pain) cortex. In addition, the length and ramification of neuronal dendrites (i.e. the neuron´s “antenna” bearing synapses to receive signals from other neurons), a measure of neuronal network complexity, was reduced in fatherless animals. Whereas biparentally raised animals have reached adult spine density values already at the age of three weeks, synaptic development in the fatherless animals is delayed, but seems “to catch up” later until reaching similar adult values compared to biparentally raised animals. However, dendritic extension and the total number of synapses per neuron was still lower in adult father-deprived animals.

These results suggest that paternal deprivation delays and partly suppresses the development of neuronal networks within orbitofrontal circuits. Thus, the father-deprived animals may suffer from hypofunctionality of this associative limbic cortical region, whose functions such as decision making, emotion and reward as well as impulsivity/impulse control and aggression may be impaired. Our study also shows that neurons in limbic cortex are continuously developing at least until puberty, which opens up an extended developmental time window, during which the detrimental brain effects of paternal deprivation may be ameliorated or compensated, e.g. by providing care by other emotionally significant family members (grandparents, new father etc), professional caretakers or peer groups.»

[Speaker’s Summary, Society for Neuroscience 2009; Lead author: Anna Katharina Braun, PhD; Otto von Guericke University Magdeburg, Germany]

Aonde nos levará a desintegração da família biparental estável avidamente promovida pela coligação da esquerdalhada, liderada pelo radical chic, com a corporação LBGT?

Sem comentários:

Enviar um comentário