Hello again, it’s been a while so I thought I’d drop in a comment or two about what I’ve found recently in the news about neurobio. I’ve lately been reading about neurotransmitters and how they bind to sites in specific neurons, instigating depolarization across the membrane of the neuron and allowing for an action potential to communicate to hundreds of thousands of other neurons. This communication between neurons in the central nervous system is relayed into actions in the peripheral nervous system resulting in behavior. But how is this synchronized? What neuron does what? What must be connected to what and why? These are all questions that may take a while to be answered, but we are finding new developments everyday.
In an article from Cornell News, I read about an experiment by James Goodson and Andrew Bass (2000) in which neurotransmitters’ role in the display of sex characteristics in plainfin midshipman fish were examined. In this particular fish, males will make vocal calls through the water that attract females who will come to the site to lay eggs for the vocalizing male to fertilize. However, a second type of male that is unable to make vocal calls waits nearby so that once the eggs are laid, he can get some free-fertilization-action.
Goodson and Bass anesthetized and stimulated the anterior portion of the hypothalamus in each fish to stimulate either a vocal call, or the female’s short grunt (a response to the male’s call). After stimulating normal calls in each fish, the neurotransmitters isotocin and vasotocin (identical to the mammalian oxytocin and vasopressin) were administered to the anterior hypothalamus of each fish. When administered, fish that normally could make calls lost the ability to do so and developed female like grunts, similar to the type II males that could not call but rather grunted like females. This meant that a trait that was typically thought to be controlled by sex (controlled or linked by the gonads) was actually independent, and regulated completely by the brain.
Who knows how many of our traits are linked to gonad development, probably much fewer than we might originally think. If I was given a good dose of estrogen would I not want to play football or wrestle with my best friends?…doubtful (it might just turn into flag football with the Vikes or a pillow fight). At any rate, we shouldn’t be so quick to make judgment calls on biology’s effects in gender behavior.