Biology 202

            The major propagator of the evolutionary process is the press for continuity, the tendency to act in order to increase the probability of passing on genes. In order to preserve ones genes, individuals are in competition, to ensure that ones genes prevail over another’s; this can be accomplished individually or collaboratively (4). While it seems logical that animals would sacrifice themselves for their young or mates, humans seem to present a special problem to this evolutionary theory in that they sacrifice themselves for abstract principles and others that are of no biological relation. A possible key to this oddity is affect hunger, an urgent need for affective bonding, which continues after the critical development period and makes mutuality and sociality as important as competition in the evolutionary process. Affective bonding provokes certain social behaviors, in others, which are necessary for normal neural development. Furthermore, only with normal neural development would an individual be able to exhibit the social behaviors essential in forming affective bonds.

All healthy humans feel like they have some degree of free will, the ability to discern and consciously choose one of a number of possible options. Free will is here defined as a conscious and deliberate process by which an individual comes to choose between multiple options, absent of any involuntary causal determination. But how does free will fit in with neurophysiology and what we know about the brain?

We know that neurons form networks. The particular connections in and between networks are a result of genetics, biology, environment, and every past experience, action, and thought. We know that our brain is governed by physical law, neurons spontaneously fire when the intra and extra cellular concentrations of NaCl change. All the molecular occurrences in our brains are results of previous ones, and cause future ones. So we can imagine that every thought we have, every action potential, is actually the result of every molecular occurrence since (and including) the Big Bang. Newtonian physics supports the idea that once the initial conditions of the universe were set, the rest of history follows inevitably. This is the central idea of the theory of determinism. If we adopt strict determinism, and imagine a thought experiment in which we possess complete knowledge, of every occurrence, every motion of every particle, every value held by every person, everything they have experienced and thought, we would be able to perfectly predict the outcome of any situation. If we are physical systems subject to determinism, there may not be room for free will in the picture.

Throughout every experience we have, there are thousands if intricate signals traveling throughout the body, especially in the brain. Every second we are unconsciously taking in information, much of which we disregard, but some of which we are able to recall at future times – this is what we know as memory. Understanding memory consolidation is a problematic thing: because of the mysterious intricacies of the brain, creating definitive experiments is very difficult, as it usually is with science. Trying to understand this role of sleep in memory consolidation is important to all of us, especially the modern student.

Dreaming is considered an activity that takes place when one enters the REM cycle during sleep. (1) Often times, most people do not remember their dreams, but it seems that as long as one sleeps long enough to enter the REM cycle, everyone dreams. Dreams are thought to be based on one's recent past experiences or declarative memories. What happens when one does not remember one's past experiences? Do they dream?

Those who suffer from amnesia have damaged their hippocampus. The damage can result from head trauma, Alzheimer's, anoxia (oxygen deprivation), or encephalitis (acute inflammation of the brain). (2) The hippocampus is in the temporal lobe of the brain and is part of the limbic system, which includes parts of the cerebral cortex that are responsible for manifesting emotions. (3) The general thought of the role of the hippocampus in memory is the hippocampus is responsible for creating new memories of experienced events. Some also believe the hippocampus plays a role in declarative memory, a component of memory for facts. (4) When there is damage to the hippocampus, it becomes very difficult to form new memories and to access memories prior to the damage; therefore amnesiacs do not have information in their brain about their recent past experiences to dream about.

Ay me, for pity! what a dream was here!
Lysander, look how I do quake with fear
William Shakespeare
Midsummer Nights Dream, Act II, scene 2

Dreams are the answers to questions that we haven't yet figured out how to ask.
Fox Mulder, The X-Files

For centuries human beings have experienced the impossible through dreams. In particular, the murky boundary between sleep and waking known as sleep paralysis has allowed us to create in our minds the stuff of fairy tales. Drifting off to sleep one often experiences curious dreams of a nightmarish quality as well as highly unusual bodily sensations. Both during hypnagogia, the period of time just before sleep, and hypnopompia, a similar state just before waking, our minds create hideous hags and ghouls, terrible enitities, the experience of alien abductions, sensations of non-existent pain and the incomparable feeling of flight [1].

             Many people have heard of the ‘placebo effect.’ Placebo pills, sometimes known as sugar pills, are the gold standard control used to demonstrate the effectiveness of drug treatments for conditions like depression, ADHD, anxiety, and so on. These pills carry no useful medication, but can affect change solely through suggestion. However, a placebo must not always come in pill form. The placebo effect can be seen in injections and, perhaps more surprisingly, surgical procedures. This, coupled with the fact that the placebo effect can occur for a range of mental health and medical conditions, illustrates that even a simple sugar pill, and the expectation that it brings, can alter both our brain and physiological state.

Ask a random person walking down the street whether scents or odours can have an impact on behaviour and the answer will undoubtedly be yes. If the person had an interest in science they might even give you a concise explanation of the process. “When odour molecules are inhaled they pass up the nostrils until they arrive at a postage-stamp sized region known as the olfactory epithelium,” she might say. “Here the odor molecules are picked up my chemoreceptors, initiating action potentials, sending messages to the brain. Once recognized by the limbic system, this information is received, interpreted and possibly initiates a response,” she might conclude. (1)

Muscular dystrophy and multiple sclerosis are probably the two most well-known movement disorders.  As a result, they have received a lot of research funding, enabling medicine to move closer to finding effective treatments and cures.  There is a movement disorder, however, that is just as serious, but often neglected.  Ataxia is a movement disorder that makes patients’ lives extremely difficult, yet is unheard of by many people.  As a result, research into treatments is significantly far behind.  Awareness of ataxia must be increased in order to drive the research that will improve the lives of its sufferers.
 

Schizophrenia is a disease that has played a significant role throughout my life. One of my uncles was diagnosed with schizophrenia when he was in college. The cause for the onset of the disease was always shrouded in mystery, however. If anyone in my family was asked why he developed schizophrenia or if there were signs of schizophrenia in him when he was younger, you would receive a different answer from each person. For this reason I always wanted to know what caused schizophrenia and why it is not always evident early on in a persons life.

When I began to research, the debates regarding schizophrenia centered around three main areas: dopamine production, genetics, and issues with neural development. In this paper I am going to focus on issues in early neural development, how neuron issues can cause schizophrenia, and why the symptoms of schizophrenia may not become evident until later in a persons life.