On November 6th 2014, I had the pleasure of listening to a lecture by Andrew Haack from the University of Utah on dopaminergic pathways in ethanol-seeking behaviour in rats. While his lecture was quite intriguing, it left me looking for more information in regards to these pathways being modulated, and what other factors have influences in these reward pathways. Additionally, I wanted to learn how the described alcohol-seeking behavioural pathway differers under the influence on other drugs.

I stumbled upon this interesting article which discussed the influence cocaine has on alcohol-seeking behaviour in rats. The researchers were interested in seeing how exposure of a drug during recovery of addiction to another drug could actually increase the addiction to both drugs.

To initiate this specific experiment, the researchers began by initiating ethanol into the rats everyday lives. In a similar manner to that described by Haack in Thursday’s lecture. This method involved slowly inducing ethanol to the rats via lever-pressing behaviours. After ‘addiction’ has occurred, the rats willingly lever-press to receive ethanol. “alcohol-seeking was assessed through the use of the Pavlovian Spontaneous Recovery (PSR) model, while alcohol-relapse drinking was assessed through the use of the alcohol-deprivation effect”. The PSR condition involved depriving the rats of their ethanol levers for the 60-minute session. For the relapse condition, rats were deprived of their ethanol levers for 7 days, before being returned to a cage with ethanol levers for their testing.

Cocaine HCl (0, 1, or 10mg/kg) was injected either immediately, 30 minutes or 4 hours before their testing sessions. In the PSR condition, researchers found that the dose of Cocaine HCl increased the rats responding to the ethanol lever compared to those with saline controls.

With the relapse condition, Cocaine HCl (1 or 10mg/kg) was injected. In the conditions where rats were given cocaine HCl immediately before being returned to their cage with an ethanol lever, there was no effect on their responding. However, in the condition where they were given Cocaine HCl injections 4 hours prior to their relapse testing, their ethanol responding was severely enhanced in comparison to the saline controls.

What we can determine from this study is that Cocaine HCl can have an effect on the ethanol-seeking and relapse behaviours. The effect of Cocaine HCl on the ethanol-relapse drinking could be indicative of a more complex interaction occuring between abuse of multiple drugs, but ultimately leading to priming of relapse with a four-hour delay.

If we are able to generalize some of these animal research studies to humans, it seems that humans with severe drug abuse issues may be prone to relapse, and these neuronal connections can be targeted in therapies to help aid relapse.

Works Cited:

Hauser, Sheketha R., et al. “Cocaine Influences Alcohol-Seeking Behavior and Relapse Drinking in Alcohol-Preferring (p) Rats.” Alcoholism, Clinical and Experimental Research 38.10 (2014): 2678-86.

In a few of my classes recently, I have been learning about Alzheimer’s disease, and it’s fascinating. A few years ago, my grandmother was diagnosed with Alzheimer’s, and I have been conducting research in this area ever since. I really want to understand the ways that neuroscientists are currently implementing treatments for this disease. Recently, I took it upon myself to conduct a research task to find out where we are with our treatment plans for those with Alzheimer’s, and I found that there were actually way more treatments than I had originally thought.

If you have no idea what Alzheimer’s is, or need a refresher, take a peek here.

First things first, there more proposed treatments for Alzheimer’s than I can count. I could create a huge list, along with their pros and cons, but that would just be tedious and boring for you to read, so i’m just going to tell you about the most exciting treatment: Deep Brain Stimulation (DBS).

Deep Brain Stimulation is a common practice in patients with both Parkinson’s and Depression. DBS involves surgically inserting an electrode to certain areas of the brain, and applying an electric current to disrupt the normal firings of neurons in these specific areas. In Alzheimer’s, the electrodes are placed in the hippocampal fornix, an output to the brain’s memory processor. It is important to note that DBS is only currently being used in clinical trials in Alzheimer’s patients, and it hasn’t yet been implemented into common treatment practices.

In a clinical trial conducted by Laxton, Lozano and colleagues at the University of Toronto, DBS was performed on six patients with Alzheimer’s disease. The researchers implanted the electrodes bilaterally (to both brain hemispheres), and conducted a series of neuroimaging techniques to determine functional and structural changes resulting from DBS.

After 12 months of this treatment, scans showed that the patients had significant increases of glucose metabolism in both the parietal and temporal cortices of the brain. Decreased glucose metabolism indicates lower activity, and thus greater impairment. Therefore, this increase in glucose metabolism indicates that the area that wasn’t functioning as well improved. The researchers  also found this through cognitive testing. These patients seemed to be at a better cognitive state than a person who wouldn’t have had this treatment would have been at. However, the researchers here didn’t have a control group, so this is an area of research that needs to be further investigated.

Currently, there are numerous clinical trials being conducted comparing the use of DBS with control patients who receive electrode stimulation on the surface of the brain, acting as the placebo group. Hopefully, with a few more years of research, the exact benefit of DBS can be determined, and if promising, can be implemented into normal Alzheimer’s treatment.

Works Cited:

Kaplan, Arline. “Deep brain stimulation: new promise in Alzheimer disease and depression?” Psychiatric Times Dec. 2012: 1. Health Reference Center Academic. Web. 6 Nov. 2014.

Brains Galore! My personal way of sharing my research into Neuroscience. For some reason, the nervous system is the most fascinating thing in the world to me, so I’m going to share it with you!

Follow me on my journey in discovering everything there is to know about the nervous system!