When a substantial number of D 2 receptors are blocked in the nigrostriatal DA pathway, this will produce various disorders of movement that can appear very much like those in Parkinson's disease; this is why these movements are sometimes called drug-induced Save image Figure 5-5. Mesocortical dopamine pathway and D 2 antagonists . In untreated schizophrenia, the mesocortical dopamine pathways to dorsolateral prefrontal cortex (DLPFC) and to ventromedial prefrontal cortex (VMPFC) are hypothesized to be hypoactive, indicated here by the dotted outlines of the pathway. This hypoactivity is related to cognitive symptoms (in the DLPFC), negative symptoms (in the DLPFC and VMPFC), and affective symptoms of schizophrenia (in the VMPFC). Administration of a D 2 antagonist could further reduce activity in this pathway and thus not only not improve such symptoms but actually potentially worsen them.
Figure 11-1. Arousal spectrum of sleep and wakefulness . One’s state of arousal is more complicated than simply being “awake” or “asleep.” Rather, arousal exists as if on a dimmer switch, with many phases along the spectrum. Where on the spectrum one lies is influenced in large part by five key neurotransmitters: histamine (HA), dopamine (DA), norepinephrine (NE), serotonin (5HT), and acetylcholine (ACh). When there is good balance between too much and too little arousal (depicted by the gray [baseline] color of the brain), one is awake, alert, and able to function well. As the dial shifts to the right there is too much arousal, which may cause hypervigilance and consequently insomnia at night. As arousal further increases this can cause cognitive dysfunction, panic, and in extreme cases perhaps even hallucinations. On the other hand, as arousal diminishes, individuals may experience inattentiveness, cognitive dysfunction, sleepiness, and ultimately sleep.
Health records shall contain the date the lot was established (if using the unique lot method), the first date the animal(s) may be shipped for slaughter considering the requirement for at least a 180 day recorded history prior to slaughter, the unique identifier, as well as record entries that indicate the date the illness was noticed, the details of the illness, the number of animals affected and date the illness was resolved. Each record event entry shall be accompanied by the initials of the person making the entry and date/time of the entry.