It is tough to discriminate exploratory behaviour and search, they are to some degree the same thing, I think. The exploratory behaviour measured the animal to take risk to search in new habitat without any specific target, but search for a particular target means animal has known the habitat and have particular aim, thus if you put animal in new habitat, you may say they are exploring, but if the animal has settled down in the habitat and knew the food place, you may say they are searching, but they are still similar.

Dear Yin, yes, exploratory and searching behaviors interweaved. Yet, results by Timberlake and White suggest that animal is able to discriminate between them. In their experiments, both satiated and hungry rats were placed in an environment completely novel for them, yet behaved differently.

Dear Valentin,

Spruijt and colleagues (http://dx.doi.org/10.1016/j.jneumeth.2014.03.001) have just done a good, critical review of the open field and other standard tests.

Best wishes

Sandra

The article of Timberlake and White had shown that hungry rats search for food using win-shift strategy of foraging, but satiated rats explore the maze on the basis of different needs. Search activity is the universal way of satisfaction of any need. In addition, exploration is a need in itself. Try f-MRI with human subjects to distinguish between exploration as a need in itself and search activity as means to satisfy another needs.The product of exploration for the sake of exploration is the cognitive map. But cognitive map can be product of any search activity for different needs. In practice, I think it is very difficult to find activity that will be exceptionally exploratory without be combined with search activity for whatever need.That is why it is better study exploratiory activity in different contexts and to take in account that search activity is a part probably of any exploratory activity in the maze and outside the maze. In Timberlake and White we had exploratiory activity dominated by hunger and exploratory activity aimed presumably at construction of cognitive map unrelated to hunger.

Alex, another explanation of rat behavior could be as follows. There are two different motivations: exploration and hunger, which manifest differently at a behavioral level. Hungry rats leave an arm as soon as they find no food there and move to another arm. Satiated rats are in an "exploration mood" and revisit the same arm to learn about its various features and its spatial relation to other arms. A cognitive map presumably could be consructed as a result of behavior driven by any of above motivations. This explanation presumes that exploratory behavior should have a property that make it possible for observer to discriminate it from a (for example) food- searching. Namely, an exploratory behavior should include sequences of repeated actions: repeated returns to the same arm in maze, repeated maneuvres in an open field test, etc. What do you think of this explanation?

Valentin, let's address your last sentence: "Exploratory behavior should include sequences of repeated actions: repeated returns to the same arm in the maze..."In addition you wrote that exploration and hunger should manifest differently at a behavioral level. Let's look at the next set of facts:

1. Sequences of repeated actions is the main characteristic of stereotyped behavior which is not accompanied by exploration and learning at all.

2. Win-stay behavior can be learned by hungry rats and then their exploration pattern based on hunger will be entirely different from that of naiive rats. Their search pattern will be sophisticated enough and will include returns to the same arm and will be manifestation of search based on hunger and not on exploration for the sake of exploration.

As I wrote in the previous message the best way to study exploration is to investigate it in different contexts. Assuming your approach that exploratory behavior requires returns to the same place I should mention that exploration does not require substantial quantity of returns. If nothing happens cognitive map will be constructed and habituation will be developing rapidly. Cognitive map constructed on the basis of this kind of exploration will be different from cognitive map developed on the basis of search activity dominated by hunger. You should be very specific about the context you want to study in order we can exchange opinions whether in this specific context you can expect pure exploration activity and for how long.

Alex, let me describe the specific problem I am dealing with: Satiated adult zebrafish is placed in a cross maze for 15 min (no food in the maze). Let maze arms be numbered 1 to 4 in the clockwise order. A typical behaviour is

A) shuttling between two adjacent arms (1212121212...) or between opposite arms (2424242424)

B) visiting arms one-by one in cickwise or counterclickwise direction (123412341234...)

C) visiting arm in some repeated order (e.g. 241241241...)

D) visiting arms in a seemingly random order.

These four patterns alternate (e.g. ADBABDC...). The order of altermation seems random. The whole behavior looks stationary: a frequency of visits to particular arm and frequency of particular patttern does not change sistematically in the course of 15 min. My preliminary explanation is that patterns A and C are an exploration of particular arms and their relative positions, while B and D could be a method to change explored arms.

Did you observe a similar behavior in rodents? What is your explanatioin for such a behavior? What modification of this experimental settings would you suggest to understand this behavior?

I can add that exploratory behavior may depend upon experience of the animal to the area, if it is first time or not, i.e. novel environment, time factor especially if the first few minutes is very important, horizontal movements (area visited) and vertical movement (rearing activity). However, searching for food is more express by continuous horizontal movements to the area.

Valentin, we did not study behavior of satiated rats in radial maze.What is the goal of your study?If you study strategies of exploratory behavior in novel environment you can provide hypothetical descriptionas you did in your last message.Take in account that in different species there are different cognitive abilities and ecology. If you are going to study exploratory behavior in complex spatial mazes try to introduce some experimental procedures to compare exploratory behavior of these subjects under no stress and no fear and no hunger and in their presence.It might be exploration strategies in different situations will be structured differently, but it might be they will be the same. One technical question: can your experimental subjects see an experimentator during their exploration activity or not? If they can we can not talk about pure exploration. In fact you have the hypothesis which should yet to be proven by experiments. You can use pharmacological experiments using anxiogenic drugs (motivational influence changing dynamics of behavior) or memory modifying or blocking drugs (to study your hypothesis on exploration of specific arms).

Valentin, thank you for your question

i am not work on the laboratory animal or fish exploratory behaviour yet........ it is interesting subject

but by observation of large animal or poultry behaviour; if the animal or bird move to food take it by mouth and throw (don't eat) and move again .......it is exploratory behaviour

but if it still and eat ........it is eating behaviour

Alex, the primary goal of the study is to compare behavioral sequences (in mazes) in fish species which differ in respect of their ecology and systematic affiliation, and also compare their behavior to published reports on rodent behavior in mazes. The idea is to see if there is an evolutionary trend in the organisation of exploratory behavior in vertebrates, and if there are some basic propertis which all species share.

We place our mazes within the foam-rubber cylinder. The source of light is ring-shaped luminescent tube. The tube is wider then cylinder and placed above it. Fish can see only eveny dispersed light reflected from porolon, but not the bulb itself, and also video camera lens right above the center of maze.

Thanks for your suggestion on memory modifying drugs. Hope we will be able to try them.

Naglaa, thanks for yor suggestion!