Operant chambers

Training and testing sessions were conducted in 10 identical isolated Col bourn operant chambers equipped with two levers mounted on either side of a motor-driven dipper. Reinforcement consisted of 3-second presentations of 0.2 ml Carnation Slender, a commercial liquid diet food, diluted 1 1 with water. Reinforcement contingencies and data recording were performed using a Rockwell AIM 65 microcomputer. 

The reactor for radiation chemical synthesis with an agitator (about 200 rotations per minute) is located in the operation chamber. Inside the reactor there is a cavity for introducing sources of y-radiation. The role of the radiation source is played by 60Co in airproof stainless steel ampules the activity of 60Co radiation is about 3000 eq Ra. The consumption degree of the energy of radiation when the sources are placed in the cavity, or the radiation coefficient of efficiency, varies from 17 to 19%. The equipment is encased in a special box made of stainless steel and plexiglass the box has intensive ventilation. 

The reactor is draft-loaded with corresponding amounts of butylbromide, tin and butyl alcohol. Then the apparatus is closed with a lid fashioned with an agitator, moved into the operation chamber and connected to all piping. After that the jacket of the reactor is filled with a heat carrier with a temperature of 90-95 °C, the contents of the apparatus are heated at agitation to 85-90 °C, the operation chamber is closed with a protective plug and sources of y-radiation are introduced into the chamber. After certain periods of time the mixture in the reactor is sampled with the help of a special sampler. 8-10 hours after the radiation has started, the reaction is completed and the sources of radiation are taken out of the chamber. The reactive mixture is loaded off and the apparatus is prepared for the next operation. 

Sessions are given in commercially available operant chambers (Coulboum Instruments, Allentown, PA 18106, USA) equipped with two response levers, and a food hopper. Initially rats are trained to press levers for food in 2-hour sessions during which a single press of either lever will result in the delivery of a food pellet. Drug discrimination training commences as... 

Experiments are conducted in commercially available operant chambers (Coulboum Instruments, Allentown, PA 18106, USA), equipped with two response levers, a food hopper and receptacle, stimulus lights and an exhaust fan. Male rats (225-250 g) are housed individually and maintained under a non-inverted 12/12 hr light/dark cycle with restricted access to food (15 g per day). Lever training begins under a continuous reinforcement schedule of food presentation. Daily sessions are terminated after 1 hour or 50 food presentations, whichever occurs first. Subsequently, the response requirement is increased by one response per daily session up to FR5. Once rats receive 50 food pellets in a single session under the FR5 schedule (typically within 5 days), food training is suspended and... 

One distinct advantage of discrimination paradigms in the operant chamber is that behavior can... 

Figure 6 An operant chamber or Skinner box for a rodent. The front wall (right) shows two response levers, below which is situated a food pellet trough. Food pellets are dispensed from a feeder located behind the front wall into the pellet trough. Above and to the left of the levers are two keys which can be illuminated with various colors and used for external or environmental stimuli. Above and to the right of the rightmost lever is a speaker through which auditory stimuli can be projected and used as external (environmental) stimuli. (Reproduced from Reynolds GS (1968) A Primer of Operant Conditioning. Glenview. IL Scott Foresman.)...

Another advantage of operant chamber-based procedures is the enormous flexibility they provide for behavioral assessment and the ease with which they can be carried out in these devices. For example, conditional discrimination problems, which are more difficult discrimination tasks, can be easily implemented in operant chambers. Matching to sample is one such method. In this task, the subject first makes a designated response to indicate that it is attending to... 

The flow instability shows up at high liquid superheats. A jet may be entrapped by the wall of the channel superimposed flange and spread out in the plane perpendicular to the direction of its motion (the Coanda effect ). The force of the jet recoil R acting on a chamber with a liquid increases with saturation pressure in the chamber, but on attaining conditions of explosive boiling-up and a jet collapse (spread along the surface of the operating chamber) the value of R decreases (Fig. 8). 

The rat is placed in an operant chamber, and after an initial priming current, a current is applied each time the animal performs an operant response such as a lever press or turning of a wheel manipulandum. 

The gradient of the compression curve (dp/d V) depends on the total fluid volume and its compressibility, which is contained in the operating chamber. Compared to... 

---