What does the optimal foraging theory claim?
- There is a trade-off between strategies for obtaining food and strategies for avoiding attack and predation
- Looking for the best quality food, but also needing to avoid predation at all costs
- Requires a maximization of fitness
What are some strategies that inform how we know where to find food?
- Taught by others, previous experience, socializing with others (i.e., communication with conspecifics)
What are the two major components of the waggle dance performed by honey bees?
1) The waggle phase (the biggest part)
2) The return phase (reset part)
What do the duration, the frequency, and the angle of the abdomen all represent in the waggle dance?
- Duration during the straight run = Encodes the distance to the food source
- Frequency of waggle = Encodes the food quality (higher frequency means more excited about food)
- Angle of the waggle = Relative to the vertical, represents the angle of the food source from the sun. Bees that have been inside the hive will accommodate for the changing solar angle
What’s the main mechanism of action for the Waggle dance?
- An accumulation of electrical charge during movement of the waggle dance
- Johnston’s organ, located in the antennas, is responsible for detecting these vibrations
T/F: The first waggle of naive bees is more error prone when they haven’t had the opportunity to observe the behaviour in older conspecifics.
- TRUE
- It still contains errors when they get older compared to control bees
- Refers back to the idea of learning from others when learning how to find food.
Which study lends evidence to the idea of prenatally learning how to identify food? What did the study involve?
- Hepper, 1988
- Exposed some pregnant rats to garlic, others not
- Litters were then cross-fostered
- Food preference was performed when they were older
- Result: There was a transmission of food preference, as pups from mothers who consumed garlic while pregnant also preferred garlic when given the option compared to the pups who did not receive prenatal garlic exposure.
Which study lends evidence to the notion of learned food preference during rodent adulthood?
- Galef, 1983
- There is a demonstrator and an observer rat
- The demonstrator rat goes in and picks between a cinnamon or a chocolate treat
- Then let the demonstrator and observer interact, where the observer will most likely sniff the breath of the demonstrator
- Let the observer pick a treat
- Result: The observer picked the same food that the demonstrator did
- A good example of one trial learning phenomenon
- Even when the animals were separated by a screen, the same occurred.
- Also specific to food
How would you define a homebase?
- Point of origin for exploration and foraging behaviour
- Rats know where home is, also able to find home in the complete dark
What are the three major mechanisms that help rats find homebase?
1) Cue response - striatally-mediated response, see home, go to it
2) Place response - can triangulate location
3) Internal cues - can navigate home
What are the two major forms of navigation?
- Allothetic - external cues (visual, auditory, olfactory)
- Idiothetic - Internal cues (proprioception, vestibular cues, sensory flow)
*May often use a combination of both to get home
What are place cells?
- Hippocampus pyramidal neurons that are active when a given animal enters a particular place in its environment
- Place cells may fire in multiple environments, but don’t fire similarly for each location.
- By understanding the activity of a bunch of place cells, you can predict the behaviour of where the animal is in its environment
Have place cells been recorded in humans?
- Yes, recorded during seizure surgery, where patients were asked to navigate a virtual environment, which was called the “taxi game.”
Which cells combined are responsible for navigation? What’s each of their function?
A) Place cell = becomes active when an animal enters a particular location in the environment
B) Place-by-direction = Sensitive to the direction an animal is moving through a place field
C) Head-direction = Sensitive to the direction of the animal’s head. Location invariant firing activity
D) Grid cell = Forms a virtual grid, allowing an animal to understand their position in space.
Where else are head-direction cells found in the brain?
- Retrosplenial cortex
- Thalamus
- Entorhinal cortex
Where are grid cells found specifically? How do they work?
- Found in layer 2 of the entorhinal cortex
- Fire in a periodic triangular arrangement
- Appear on the first entrance in an environment
- Stable firing pattern (give info on distance and size)
What’s the relationship between exposure to environments and place cell activity?
- Becomes refined as a function of exposure (tuned over time)
- Remains stable over time, unless the environment changes
What are place cells responding to?
- Place cells respond to distal and local cues
- This was determined using the double rotation protocol, where the rat was rewarded at a specific location in the pool rotation, and then place cells started to respond to this area.
T/F: Firing rate of place cells do not increase with the speed of which the animal moces through the place field.
- FALSE
- Firing rate does increase as a function of speed with which the animal moves through a place field.
What are three major theories for place cell function?
- The role of place cells in the production of a spatial map
- The role of place cells in path integration
- The role of place cells as a specialized operation that fits into the general episodic memory function (informs memory system about location)
Which evidence indicates that place cells play a role in long-term potentiation?
- Used an NMDAR1 CA1-knockout mouse
- Eliminated subunit of NMDA receptor in CA1
- A prevention of LTP-induction in-vitro
- Results: Knockout results in larger and “fuzzier” place fields
*NMDAR1 = important for plasticity - LTP is involved in the formation of spatial maps in the hippocampus
