Brief Description
In this study, you will be examining whether a particular drug (7,8-DHF) that acts as a "cognitive enhancer" in rodents can improve outcomes for exposure therapy for PTSD.
The Drug
7,8-DHF* acts as a "BDNF mimetic", meaning that it mimics the effects of BDNF (discussed in your Neuro Lectures), and promotes neuroplasticity. When paired with a learning event, 7,8-DHF can help animals learn better/faster (see preparatory readings).
*7,8-DHF is not currently safe for use in human populations, but for the purposes of this report, we are pretending that it is!
Exposure Therapy
Exposure therapy for PTSD uses principles of extinction learning (further discussed in Learning and Motivation lectures) to reduce the fear response to traumatic memories and help alleviate the symptoms of PTSD.
Current Study
This study is designed to examine two factors: 1) Behavioural Intervention (whether participants received Exposure Therapy or a Control Intervention), and 2) Drug Status (whether participants received 7,8-DHF or Placebo). This is what we call a "2x2 study", meaning that there are 2 factors (Behaviour and Drug), and each factor has 2 levels (Exposure/No Exposure; 7,8-DHF/Placebo).
Getting Started
1) View the recommended sections of the preparatory readings provided.
2) Examine the Methods and Results sections provided.
3) To familiarise yourself a bit with the field, do some independent exploration of scientific literature related to PTSD and exposure therapy (Google Scholar is fine at this stage). Ask yourself questions like: What are the strengths/weaknesses of exposure therapy for the treatment of PTSD? Why might we be searching for pharmacological adjuncts? What other drugs have been tried before? Were they successful?
Preparatory Readings
Check out the indicated sections for the following readings:
1. Cognitive Enhancers for Exposure Therapy_Milad.pdf
This is a review that gives you a nice introduction to Exposure Therapy, Extinction, and Cognitive Enhancers. Basically, cognitive enhancers are pharmacological aids that enhance learning. Many researchers try to identify drugs that work to promote fear extinction in rats or mice with the goal of eventually being able to offer them to people seeking exposure therapy for disorders like phobias, anxiety, or PTSD. In theory, these drugs would enhance the learning that takes place during therapy, making the process more effective. I would suggest reading the Abstract, the Intro, and trying to tackle one or two of the examples (D-Cycloserine and estrogen would be my picks -- don't stress about the biological mechanism details).
2. PTSD Exposure Therapy_Oxytocin.pdf
This is a small preliminary study that didn't reach significance, but it's very similar to the methodology that we'll be using in the research report. This one is pretty clearly written, so tackle as much of the Abstract, Intro, and Methods as you can (but don't spend too much time trying to understand every detail). You can then skip to the end and have a look at the results on page 15 to see how PTSD symptoms seemed to reduce more in the Oxytocin group than the Placebo group (again, not a significant difference, but it was a small sample size).
3. 7,8-DHF Extinction_Andero.pdf
This one is rough, but you don't need to read much of it! I've highlighted brief sections on p.1, 2, 12, and 13 that I'd like you to take a quick look at, and for each of these sections I've added explanatory comments. This just covers the basic mechanism of a drug called 7,8-DHF, and shows how it enhances learning in mice. As you will see, if this drug is given before fear conditioning, mice learn fear better. If it's given before fear extinction, they learn extinction better.