The Neurodevelopmental Behavioral Core (NBC) is located in the Karp building and has been designed to provide a time-efficient and cost-effective service for the comprehensive characterization of complex behaviors in mouse models of neurodevelopmental disorders, with emphasis on facilitating genetic analyses of complex traits. The NBC aims to provide the facilities and advice to test novel therapeutic drugs and interventions in mouse models of human disorders and diseases, greatly increasing translational research capacity at Boston Children's Hospital. One of the unique features of the NBC is the availability of specialised environments for studying the interaction between "nature and nurture" e.g. dark rearing, sound and light isolation and standardised environmental enrichment. The NBC provides both the necessary equipment, protocols and training for studying neurodevelopmental disorders, focusing not just on “snapshots” in time but on developmental milestones. The NBC is equipped to perform batteries of behavioral tests to thoroughly phenotype specific social, emotional and cognitive behaviors, as well as motor, auditory and visual function and the general health of the animals. Where possible analyses have been automated to improve inter-rater reliability and remove subjectivity. We use Ethovision XT video tracking systems to monitor activity in specific tests of behavioural performance and have other video cameras and infra-red beam break systems for recording other behavioral activity for offline analysis. The NBC has 2 EEG systems - a tethered system with capacity for up to 6 subjects and a telemetry system for up to 8 subjects. There is also capability to measure ECG and respiration in conscious mice without need for surgery.
Staff of the NBC are very willing to work with PIs and Fellows to develop and validate new behavioral outcome measures related to neural development and disorders of development that will contribute to a greater understanding of behavioral changes during development and how disorders in these lead to altered function.
The behavioral facility will provide a unique opportunity for training scientists and teaching graduate and undergraduate students in the measurement of the behavioral outcomes of developmental disorders. We fully endorse the ARRIVE guidelines which are designed to improve the reporting standards of in vivo experimentation and encourage scientists that use the NBC to read the ARRIVE guidelines and use them as a checklist PRIOR to designing their experiments.
The NBC is under the direction of Dr Michela Fagiolini and managed by Dr Nick Andrews. Ms Tiffany Wang B.Sc. and Ms Sonia Xu B.Sc. are the NBC's dedicated Research Assistants. Dr Andrews and Dr Fagiolini are backed up by an internal advisory committee NBC and an external advisory committee composed of experts outside of Boston Children's Hospital that review performance and services on an annual basis. The NBC is under the expert administrative guidance of Amy Weinberg, MPH, Administrator of the IDDRC.
Facility houses three of these instruments.
We have the capability to record sleep and wakefulness using EEG and EMG. Mice are housed in regular home cages and the sleep/wake activity measured using a telemetered (DSI) system or in open field arenas using a tethered system.
FPS can be used to measure ‘conditioned fear” which is an emotional learning process induced by training animals to understand that a conditioning stimulus (CS) e.g. pure tone will signal the delivery of an unconditioned stimulus (US) which is aversive. Testing then takes place in the absence of the US and the startle response to a loud white noise stimulus (95-110dB) is found to be of higher magnitude in the presence of the CS (the noise tone) than the startle response to the same loud noise stimulus in the absence of the CS. The enhanced startle response in the presence of the CS is due to the anticipatory fear of receiving a footshock and is a measure of fear that can be recapitulated in human volunteers demonstrating the translational value of this paradigm.
The DigiGaitTM system provides numerous spatial and temporal indices of posture and gait dynamics, including: Stride length, Stance width, Stance duration, Swing duration, Braking duration, Propulsion duration, Stride frequency, Paw Angle. DigiGaitTM allows imaging the ventral side of mice as they walk on a motorized transparent treadmill belt. One high-speed camera captures the dynamics of the paws and corresponding limbs as they approach the belt during the braking phase of stance, or move away from the belt during the propulsion phase of stance just before the swing phase. The DigiGaitTM system fully quantifies the stance and swing components of stride.
This test is part of the neurological assessment battery. It provides a measure of the force that is required to make a mouse release its grip (i.e. it measures muscle strength). The apparatus (i.e. grip-strength meter) consists of a grasping trapeze connected to a force transducer.
The holeboard can be used to measure simple exploration or it can be used as a simple measure of attention. The arena consists of a perspex box with a floor that contains shallow holes. To measure exploration the mouse is placed in the arena at one side and allowed time to explore. The number of holes visited, time spent sniffing and distance travelled around the arena are measured. For a simple measure of attention, the mouse is placed in the holeboard on 4 separate days and the same measurements of exploration taken. On Day 5, one of the holes is baited with an inanimate object and the mouse once again placed in the arena. If the mouse has a normal attentional capacity it will notice the object is new and direct its exploration to that hole and therefore the amount of time spent investigating will be greater than the previous day.
The InfraMot system is designed to register total activity of an animal by sensing body-heat. The sensor assembly is mounted on top of the Opticages. The system is suited to short-term locomotor activity studies where total activity is a sufficient indicator of motor function or to long-term circadian studies.
The (Morris) Water Maze tests Spatial Memory. The water maze consists of a pool, with a hidden platform submerged just below the water surface. Over a period of days (trials), the mouse learns to escape from the water by locating the platform with the help of visual cues located on the walls outside the maze. In a second phase of the experiment, the platform is removed altogether, or placed in another quadrant, to investigate the animal’s perseveration or cognitive flexibility i.e. how quickly it can learn that the platform is not in the original location. The animal behavior is recorded and analysed using video tracking with Ethovision 8.5XT software. Several parameters can be analysed to measure performance such as:
- Latency to reach the platform.
- Average distance to platform: Gallagher’s proximity.
- Total distance swum until reaching the platform.
- Total percentage of time spent in specific quadrant.
- Mean swimming velocity.
- Direction of movement relative to the platform (heading).
Basic vision can be determined by measuring (1) simple reflex responses to visual stimuli e.g. the blink reflex (tested by approaching the eye with the tip of a clean cotton swab) and papillary constriction in response to a strong beam of light directed at the eye, and (2) by performing the visual cliff test that measures gross visual ability of the mouse to see the drop-off at the edge of a horizontal surface.
The purpose of the Rotarod test is to assess the mouse’s sensorimotor coordination and/or fatigue resistance. The test is sensitive to damage of the basal ganglia and cerebellum and to drugs that affect motor function. Two slightly different variations of the Rotarod test can be performed: (i) using a fixed speed (~ 7 – 20 rpm) or (ii) a steady rate of acceleration (up to a set maximum speed of approximately 40 rpm). In both scenarios, the latency to which each individual mouse falls from the rod onto the sensing platform below is recorded automatically. If an animal does not fall off the rod then the test ends after a maximum allotted time (typically 2-5 min). Each of these procedures may be repeated with an appropriate inter-trial interval in order to assess motor learning or to provide a stable baseline performance level.
Facility houses two of these instruments.
Whole Body Plethysmograph chambers enable researchers to monitor breaths-per-Minute (BPM), Tidal Volume, Minute Volume, Inspiratory time, Expiratory time, Pause and PenH from unrestrained animals.
The core will provide facilities and expertise in a variety of standard aseptic surgical services such as:
- Infusions of compounds, antibodies, oligonucleotides, proteins, and viral constructs.
- Implantation of cannulae and electrodes
- Subcutaneous Drug Delivery Systems: Osmotic minipumps, drug pellets, drug capsules.
The NBC trains users in the different behavioral protocols and helps with data analysis where required. A major role of the NBC will be to discuss with investigators certain key considerations that need to be included in the design of their studies to increase the chances of getting the best from their experiments. In addition we host an annual workshop for users of Noldus Ethovision software and training in the use of specific instruments by manufacturers e.g. ECGenie and Digigait (Mouse Specifics). The NBC will provide training in blood and body fluid collection and will advise on drug treatments and pharmacokinetic analysis, including access to Mass Spec facilities at HMS and CHB.
We host an annual symposium which consists of talks by internationally recognized neuroscientists with recent speakers including Professor Jackie Crawley (UC Davis), Joshua Gordon, PhD (Columbia University) and members of our advisory committees.
The Core has 6 licences to acquire data using the latest version (11.5) of Ethovision XT. There is a disk that can be copied by users of The Core to install the analysis software onto their own pc in order to analyse data. This does not enable data acquisition. Furthermore this program does not work on Mac computers so data analysis must be done on a windows pc.
The Core has a Platinum Service contract with Noldus Information Technology so users may contact Noldus at anytime to discuss problems with data acquisition or analysis.