W&M Honors Fellows

I apologize for not writing a post last semester but to say Fall Semester flew by would be an understatement. It took a while to get accustomed to my new positions and responsibilities on campus so I unfortunately couldn’t focus as much of my energy on my thesis as I would have wanted. I am the President of Circle K International (CKI) and have 16 board members and over 60 club members to organize, coordinate, and keep happy. I set out some lofty goals and am proud to say that we achieved a majority of them. In addition to that new position, I am also one of two Student Directors of Branch Out Regional Alternative Break Program on campus. Katie, my co-director, and I had to organize training for our site leaders, lead a retreat, and advice weekend service trips throughout the semester. We now have a hold on how to best execute plans and thereby foresee only smooth sailing from now on. Now that I have a handle on my extracurricular, I have my eyes set on completing a well-researched honors thesis.

All that being said, it doesn’t mean last semester was unproductive. I attended the 44^th Annual International Society for Developmental Psychobiology (ISDP) Conference in DC. Mark Hayden, a fellow senior, and I presented two posters at the conference, one being the founding research on which my thesis builds off of. You can find the abstract and others here: http://isdpcentraloffice.org/abstractlist.asp but I’ll also include them at the bottom of this post. I extremely enjoyed the conference- being able listen to speakers from around the globe talk about interesting new research in the field was thrilling! Also, being reunited with my adviser, Pam Hunt, who spent the semester in Canada for her sabbatical was another bonus. We had the opportunity to discuss my thesis and get a handle on the progress.

In terms of my actually research- I completed phase three. Phase three is an evaluation of how much the rats learned and what the effects mercury and Vitamin E had on their abilities to learn. For this phase, I watched videotapes of my rats and assess if they were freezing or not. Freezing is the complete absence of movement and a behavior that rats exhibit if they are experiencing fear. Since they should have learned to associate the light with a shock, when exposed to only the light they should have been scared and hence frozen. So, more freezing equates to more learning. After all the videos were watched and scored (by both Pam and myself), they need to be statistically analyzed. Since I didn’t take pysc stats (I took statistics in the math department) I was unfamiliar with SPSS- a computer statistics program. Pam helped me by running the program and we just got out results last week. I’ll save the results and implications for another post since I have some major literary research to do to explain why our results came out the way they did. I won’t spoil anything- so you’ll just have to wait.

Now, I am just preparing for the Honors Colloquium. I am presenting on Wednesday February 15^th at 12pm in Blow 201. Come out and hear about the results if you don’t want to wait for another post.

Otherwise, take care until next time.

 

Here are the abstracts:

Abstract Title: NEONATAL MERCURY IMPAIRS CONTEXT FEAR CONDITIONING IN RATS
Abstract:
NEONATAL MERCURY IMPAIRS CONTEXT FEAR CONDITIONING IN RATS. K. Kapetanovic & P.S. Hunt, Department of Psychology, College of William & Mary, Williamsburg, VA 23187. kkapetanovic@email.wm.edu. Hayden et al. (ISDP, 2011) report that neonatal mercury exposure has a profound effect on hippocampal function in rats, as assessed with a trace fear conditioning procedure. To further examine mercurys toxic effects on hippocampal function the present experiment utilized the context pre-exposure facilitation effect (CPFE), a procedure that is highly sensitive to hippocampal damage. If animals are shocked immediately upon placement in the context, there is little evidence of learning relative to a standard conditioning control in which animals are allowed to explore the context for several minutes prior to shock delivery. This immediate shock deficit can be overcome by pre-exposure to the context 24 h prior to training. In the present experiment mercury (0 or 1 mg/kg) was injected once per day on postnatal days (PD) 4-9, and subjects were trained on PD 23-25. Subjects were pre-exposed to the Same context as training, to a Different context or given No pre-exposure. On PD 24 animals were given a single shock immediately upon placement in the training context. Other animals were trained using standard context conditioning procedures. On PD25 animals were tested for freezing to the training context. Results indicate that mercury-exposed animals failed to show the CPFE whereas control subjects did. However, mercury-exposed animals showed learning that was equivalent to that of controls following standard context conditioning. These results, along with Hayden et al.s, indicate a particular sensitivity of the hippocampus to the toxic effects of neonatal mercury exposure. [Research supported by grant AA015343 to PSH]

Abstract Title: SENSORY PRECONDITIONING AND SECOND-ORDER CONDITIONING IN AN ANIMAL MODEL OF FETAL ALCOHOL SPECTRUM DISORDER
Abstract:
SENSORY PRECONDITIONING AND SECOND-ORDER CONDITIONING IN AN ANIMAL MODEL OF FETAL ALCOHOL SPECTRUM DISORDER. P.S. Hunt, R.C. Barnet, K. Kapetanovic, A. Pudasaini & E.A. Wingfield, Department of Psychology, College of William & Mary, Williamsburg, VA 23187. pshunt@wm.edu Recently, research with animal models of Fetal Alcohol Spectrum Disorder (FASD) has shown that alcohol-exposed rats are impaired in higher-order learning processes (e.g. trace fear conditioning, contextual fear conditioning), but appear unaffected in simple Pavlovian delay fear conditioning. The present experiment studied two other higher-order learning tasks, sensory preconditioning (SPC) and second order conditioning (SOC), in a rat model of FASD. Rats were given 5.0 g/kg ethanol on postnatal days (PD) 4-9 or sham intubations. On PD 30 subjects began training. On one day, animals were given light-shock pairings (L+) and on the other day they were given simultaneous, serial, or unpaired presentations of a tone with the light (TL). The two procedures differed in the order of these training sessions. In SOC animals were first trained with L+ followed by TL. In SPC the TL phase preceded L+ training. All animals, regardless of ethanol exposure or training procedure, showed high levels of fear (freezing) to the first-order light CS. Also, ethanol had no effect on freezing to the second-order CS, the tone, in the SOC procedure. In contrast, ethanol-exposed animals were significantly impaired in learning about the higher-order tone in the SPC procedure. These results indicate an ethanol-induced impairment in sensory integration in the SPC procedure. These findings suggest that SPC is sensitive to the effects of neonatal ethanol exposure and also lend support to the hypothesis that different neural systems are involved in learning in these two procedures. [Research supported by NIAAA grant AA015343]

Abstract Title: NEONATAL MERCURY, HIPPOCAMPUS-DEPENDENT LEARNING AND ANXIETY IN A RAT MODEL
Abstract:
NEONATAL MERCURY, HIPPOCAMPUS-DEPENDENT LEARNING AND ANXIETY IN A RAT MODEL. M.A. Hayden,¹ K. Kapetanovic,¹ D.A. Cristol² & P.S. Hunt¹, ¹Department of Psychology and ²Department of Biology, College of William & Mary, Williamsburg, VA 23187. mahayden@email.wm.edu. The toxic effects of mercury exposure during prenatal development have been known since the 1950s when high levels of environmental mercury contamination in Minamata, Japan were found to affect neurological function in the children. Since that time a number of case studies have been reported showing cognitive and behavioral effects of gestational mercury exposure. In animal models gestational exposure has produced many of the symptoms of Minamata Disease, although cognitive impairments have not been consistently reported. One possible reason for this is that most of these studies ceased mercury exposure at birth, thus missing the third trimester period that occurs after birth in rodents. Here, we modeled mercury exposure during the postnatal brain growth spurt by exposing neonatal rats to mercury (0, 1 or 2 mg/kg, i.p.) once per day on postnatal days [PD] 4-9. Subjects were trained on PD30 in either a delay or a trace fear conditioning procedure. Other animals were tested for exploration, general activity and anxiety-like behaviors in an open field and an elevated plus maze. Results indicated that trace fear conditioning was affected by mercury at a lower dose (1 mg/kg) than was delay fear conditioning. We also observed reduced anxiety in 2 mg/kg mercury-exposed animals, but no change in activity levels. These results suggest a greater sensitivity of the hippocampus to the toxic effects of mercury, although amygdala function also appears to be affected by higher doses. [Research supported by grant AA015343 (PSH) and a grant to the Department of Biology from the Howard Hughes Medical Institute (DAC)]