Physiological and Behavioral Effects of Hyperinsulinism on Goldfish

Likewise, too much insulin in the body will causeglucose levels to plummet below normal levels. Ifthe drop in insulin levels is not too severe, theorganism will experience mild symptoms <strong>of</strong>fatigue, anxiety, tremors, <strong>and</strong> hunger. However, ifthe drop in glucose through very high levels <strong>of</strong>insulin grows more extreme, the organism canexperience insulin shock. Insulin shock occurswhen the blood glucose levels drop to such lowlevels that the brain is no longer sufficientlyprovided with glucose <strong>and</strong> begins to malfunction.Symptoms <strong>of</strong> insulin shock include disorientation,convulsions, unconsciousness, <strong>and</strong> if leftuntreated will result in death. Fortunately, weshall see that insulin shock is easily reversed byproviding a rapidly metabolized form <strong>of</strong> glucoseto those affected.Many people with diabetes mellitus needinjections <strong>of</strong> insulin to maintain blood glucosehomeostasis. Therefore it is easy for us to use thisavailable source <strong>of</strong> injectable insulin in behavioralexperiments in our laboratory. We shall usegoldfish to demonstrate the effects <strong>of</strong>hyperinsulinism on goldfish behavior. Since theaction <strong>of</strong> insulin is similar in all vertebrates, wecan make some generalized conclusions about ourresults with many other species.There are three very distinct behavior patterns thatcan be observed in goldfish. One, mouth gapingbehavior, is an indication <strong>of</strong> the fishes’metabolism. As the metabolism <strong>of</strong> the fishincreases, the mouth gaping behavior increases ingoldfish. To observe mouth gaping behavior,researchers simply count the number <strong>of</strong> times afish opens its mouth in a set time frame. Asecond behavior, operculum movement, is abehavior that signifies oxygen consumption in theanimal. As the number <strong>of</strong> operculum movementsincreases in a given unit <strong>of</strong> time, it is associatedwith decreased overall oxygen within the body.The operculum movements are an attempt by thefish to increase the flow <strong>of</strong> water through the gillsto increase oxygen absorption. The third behavioreasily viewed in the goldfish is pectoral finmovement behavior. The movement <strong>of</strong> thesefins, the “arms” <strong>of</strong> the fish, are vital for balance,directional movements, <strong>and</strong> maintenance <strong>of</strong>position in the fish. The number <strong>and</strong> quality <strong>of</strong>the fin movement signifies the overall physicalstate <strong>of</strong> the fish.Experimental Materialsgoldfishinsulinsyringes <strong>and</strong> needlesicebeakerswhite papertimersglucose solutionExperimental Procedure —Normal Behaviors in theGoldfishWhat is the normal behavior pattern in goldfish?1. Obtain a beaker <strong>and</strong> fill it with 1–1.5 cm <strong>of</strong>water.2. Place one goldfish in the beaker. Allow itto acclimate for 5 minutes.3. Begin observing the behavioral patterns <strong>of</strong>the fish in the following order: mouthgaping, operculum movements, pectoral finmovements. Observe each behavior for aperiod <strong>of</strong> two minutes. Have each member<strong>of</strong> your group record these behaviors (thiscan be simultaneous or consecutive viewing... you as a group must decide <strong>and</strong> remain2