Maternal Care & Learning Capabilities of Offspring

A recent study by Dong Liu et al. utilized rat mothers and their litters to examine a potential correlation between variation in types of maternal care with variation in related offsprings' cognitive abilities. This study offers a comparison between two types of mothering. The first type of mothering, which I will refer to as Type 1, is characterized by an elevated level 'hands-on' attention: a Type 1 mother engages in frequent licking, frequent grooming, and arched-back nursing of the pups in her litter. A Type 2 mother exhibits a lesser level of 'hands-on' attention: less frequent licking, grooming, and nursing of her pups. At this point I would like to make clear that there is of course a range of mothering types; there are several more than Type 1 and Type 2, however for the purposes of this study and of clarity, I will describe mothering types in this binary manner. The Liu et al. research team ultimately found variations at the neuronal level that varied with respect to the type of mothering with which the offspring were raised. Offspring of Type 1 mothers exhibited markedly different activity at the neuronal level, with increased expression of NMDA receptor subunit and BDNF mRNA. Although this sounds overly-complex, what this finding truly means is that offspring of Type 1 mothers displayed increased innervation of the hippocampus, and it is this increased innervation that Liu et al. has deemed the differentiating factor between the offspring of Type 1 versus Type 2 mothers.In particular, this variation in hippocampal development is associated with enhanced spatial learning and memory capabilities. Therefore, offspring of Type 1 mothers became 'wired' to exhibit an enhanced level of spatial learning and memory, while Type 2 offspring simply did not demonstrate the same capabilities.

Neuron density and cell field volume in various parts of the hippocampus

The results of this study suggest that variations in maternal care can create correlative variations in neural function at the molecular level--at the very core of neural learning processes. Hands-on maternal care in mice created enhanced learning capabilities in offspring due to increased innervation of the hippocampus. Alternatively, mothers with low-frequency care raised offspring who did not demonstrate the same level of cognitive learning abilities. These observations should be quite indicative of similar responses in human maternal interaction; however the certainty of the correlation can not be unquestionably determined without a human study.

To view the Liu et al article, follow this link.