Preface ix^through several possible mechanisms including endometrium lining thinning,
inhibition of the corpus luteum, thickening of the cervical mucus and
retardation of sperm motility. LNG is well tolerated and is considered to be
safe. No links to pregnancy complications or congenital disorders have been
found. Lastly, the safety of breastfeeding is well established with no
deleterious effect on the nursing infant.
Chapter 5 - Childhood obesity has been on the increase over the last
several years, and has been described as reaching epidemic proportions in the
developed world. Current estimates are as high as 30% of children in the
United Kingdom are overweight or obese. Obesity in childhood has brought
with it the rise in previously rare childhood complications of type 2 diabetes,
non-alcoholic fatty liver disease and significant mental health issues relating to
obesity. Many public health and health-economic authorities have focused on
the significant health and financial burden that could be posed by the
possibility of entire generations of children growing up to be overweight or
obese adults. The challenge faced by the global community is in managing
these children and adolescents with obesity. Drug therapy is limited, and
weight-loss outcomes from community based programmes have been limited.
More focus has recently been placed on surgical interventions – but these have
proved controversial in many sectors of the society.
Chapter 6 - The posterodorsal medial amygdala (MePD) is a sexually
dimorphic area that contains one of the highest concentration of gonadal
hormone receptors in the rat brain. It modulates the timely display of
reproductive behavior in both male and female rats. Dynamic changes affect
the local synaptic processing along the estrous cycle. These changes are
evident in the number of synapses made directly on dendritic shafts or the
complex modulation of the density and the shape of dendritic and somatic
spines during the short-term proestrus phase, when the levels of estradiol and
progesterone reach a peak in circulation. That is, the MePD of females in
proestrus has an increase in the number and diversity of somatic spines. In
contrast, there is a marked reduction in the density of dendritic spines during
this same phase. Spines are specialized postsynaptic neuronal elements that
modulate mainly the excitatory neurotransmission. These findings indicate that
the female rat MePD modulates the synaptic input in a complex and dynamic
way prior to influencing other interconnected brain areas relevant for the
neuroendocrine secretion needed for the ovulation and the display of
proceptive behavior. Furthermore, substitutive hormonal therapy to adult
ovariectomized females do not resemble the physiological variations in the
normally cycling rat. This synaptic organization changes once more when