Precise fluid intake measurement can be extremely important in behavioral neuroscience studies. Accurately measuring the amount of fluid a rodent consumes provides crucial insights into their physiological and behavioral responses. In this blog, we will delve into the significance of precise fluid intake measurement, highlighting the Drinko Measurer. With its enhanced features like precise and accurate drink measurement, leak-free sipper tube, and multiple sizes designed to fit, the Drinko Measurer has improved the way researchers track and analyze fluid consumption in rodent studies.
The Importance of Accurate Fluid Intake Measurement
Accurate measurement of fluid intake is vital in behavioral neuroscience studies for several reasons. Firstly, it allows researchers to evaluate the impact of specific treatments, drugs, or interventions on an animal’s drinking behavior. By precisely quantifying fluid intake, researchers can analyze the effects of these factors on hydration levels, metabolism, and overall physiological state. Secondly, precise measurement enables the detection of subtle changes in drinking behavior that may be indicative of altered cognitive or emotional states. This information is crucial for understanding underlying behavior and for drawing accurate conclusions in neuroscience research.
The Drinko Measurer: Leak-Free Fluid Intake Measurement
The Drinko Measurer has emerged as an ideal tool in the field of behavioral neuroscience for accurately measuring rodent fluid intake. This innovative device provides numerous benefits that enhance the accuracy of fluid intake measurement. Equipped with a double-ball bearing, the Drinko Measurer offers precise volume measurement, ensuring reliable data collection every time. Researchers can track and record the exact amount of fluid consumed by rodents, enabling precise analysis and comparison between experimental groups.
Explore the Drinko Measurer for Precise Fluid Intake Measurements!
The Drinko Measurer incorporates a leak-free sipper tube system, addressing a common challenge in fluid intake measurement. With conventional setups, fluid leakage can lead to inaccuracies and potential confounding factors. However, the Drinko Measurer’s leak-free sipper tube eliminates this issue, ensuring that the measured fluid intake truly represents the consumed amount. This feature enhances the reliability of the data and allows researchers to draw more accurate conclusions regarding the effects of various treatments or experimental conditions on fluid intake.
Versatility and Adaptability with Multiple Sizes
The Drinko Measurer offers researchers the flexibility to adapt to different experimental requirements by providing multiple sizes of sipper tubes. Whether researchers are working with mice, rats, or other rodent models, they can select the appropriate sipper tube size to ensure accurate measurement. This adaptability makes the Drinko Measurer a valuable tool for various behavioral neuroscience studies.
Accurate measurement of fluid intake is essential in behavioral neuroscience studies, as it provides valuable insights into the physiological and behavioral responses of rodents. The Drinko Measurer, with its accurate drink measurement, leak-free sipper tube, and multiple sizes, has revolutionized fluid intake measurement. By utilizing this advanced device, researchers can ensure precise data collection, eliminate confounding factors, and enhance the reliability of their findings in behavioral neuroscience research.
In the realm of neuroscience research, a groundbreaking technique has emerged known as wireless optogenetics. Wireless optogenetics is a fusion of wireless technology and light stimulation that allows for precise control and manipulation of neural activity in real time. In this blog, we will explore the remarkable applications of wireless optogenetics and its potential to advance our understanding of the brain. We will also delve into the limitations of traditional tethered systems and the numerous benefits offered by wireless optogenetic technology.
The Power of Optogenetics
Optogenetics utilizes light-sensitive opsins to precisely control and modulate specific neurons. By introducing genetically engineered opsins, researchers can manipulate neural activity with remarkable precision, enabling the study of neural circuits, brain activity, and neurological disorders.
Advancing Neurological Research:
Wireless optogenetics holds promise in studying neurological disorders like Parkinson’s disease and epilepsy. With wireless technology, precise optical stimulation and neural modulation can be achieved, offering potential therapeutic approaches and novel treatment strategies.
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Wireless optogenetics enables researchers to investigate neural circuits with exceptional accuracy, shedding light on the functional roles and connections between brain regions. This detailed understanding enhances our knowledge of brain function, information processing, and behavior generation.
Wireless Technology and Neurophysiology
Integration of wireless technology in optogenetics revolutionizes neurophysiology. Researchers can study neural activity and behavior in freely moving animals, acquiring real-time data for comprehensive analysis. This integration opens new avenues for studying the brain in natural contexts.
While wireless optogenetics has revolutionized neuroscience, ongoing efforts focus on miniaturizing wireless devices, optimizing power consumption, and developing advanced data analysis techniques. Integration with other cutting-edge technologies holds promise for unraveling the complexities of the brain.
In conclusion, wireless optogenetics with its precise control of neural activity through light stimulation transforms neuroscience research. It provides unprecedented insights into neural circuits, brain activity, and neurological disorders. By combining wireless technology and optogenetics, we are poised to unlock groundbreaking discoveries that will reshape our understanding of the brain.
Head-fixation is widely used in the field of behavioral neuroscience in awake behaving animals to better understand the cortical involvement in animal behaviors. Our understanding of topics such as associative learning, sensory perception, navigation and motor control have been greatly improved by head-fixed experimental preparations. The restraint and motion minimization of the animal’s head minimizes noise and motion artifacts often seen in freely moving studies, which allows for stimulus control studies, perturbation experiments, neural recordings and in vivo cellular imaging. It also simplifies the experimental set-up design and data analysis, allowing for chronic and long-duration studies as many systems facilitate accurate repeated alignment between the animal’s head and the restraining system.
Most recently, head-fixation has been used alongside advanced techniques such as high-density electrophysiology recordings and two-photon imaging to investigate neural circuits in vivo that would not be possible to study in freely moving subjects.
2. Limitations to Most Head-Fixation Systems
However, there are a number of limitations that need to be considered when carrying out large-scale monitoring of neuronal activity under head-fixed operant conditions.
Many models of head-fixation assume that head movements don’t occur when the animal is restrained. Some subtle movements of the animal’s head that cannot be easily observed or taken into consideration when doing data analysis can result in noise or artifact production. This can lead to significant confounding variables, with a misinterpretation of neural activity associated with animal behavior. Choosing the correct head-fixation instrumentation reduces the risk of confounding variables associated with involuntary head movements.
Measuring motor responses in rats or mice by monitoring whisker movements and licking behavior have been used in conditional behavioral tasks in the past. However, these motor movements are driven by a pathway in the brain involving automatic repetition that involves the brainstem. Identifying a reliable, measurable movement under operant learning conditions is imperative to accurately associate cortical activity with behavior.
3. Skilled Motor Movements in Operant Conditioning
Skilled motor movements are a good measure of operant learning, as rats and mice are naturally able to perform voluntary skilled motor movements using their forelimbs. Skilled movements are intentional isolated movements with specific parts of the body, which require the recruitment of different neural pathways that contain different subtypes of neurons firing with synchronicity. A number of operant learning paradigms can be studied by measuring forelimb movement response under head-restraint conditions alongside high-density electrophysiology recordings or two-photon imaging. It is important to consider the type of restraining system to use when studying voluntary forelimb movement in rodents.
4. Case Study – Microcircuitry coordination of cortical motor information in self-initiation of voluntary movements
Using the TaskForcer (O’Hara) restraining system, The Isomura* group at the University of Tokyo uncovered functional diversity of pyramidal cells and the uniformity activation of fast-spiking interneurons across all cortical layers in the expression of trained rodent voluntary movement. Furthermore, they identified a pattern of excitatory synaptic interactions among neighboring neurons that play different roles in self-initiated voluntary forelimb movement.
Juxtacellular and multi-unit recordings were taken from the motor cortex of 74 rats who were head-restrained and trained to repeat voluntary forelimbs movements. The juxta-cellular recording technique was implemented as it provides accurate spike events and morphological features for a cortical or subcortical neuron. The multiunit recording technique is useful for exploring the synaptic connectivity of many neurons simultaneously while remaining blind and unbiased.
A multi-rat task-training system was developed to simultaneously train up to six adult rats on an operant voluntary forelimb-movement task. During the operant trials, the trainee rats quickly learned the relationship between the lever and the water reward. This led to the trainee rats casually grabbing the lever with their right forelimb for their reward instead of struggling during the restraining process.
All 74 rats were successfully able to perform the operant motor task in just 8 days of training. Post training, the rats were transferred to a recording room where they were able to perform the same casual operant motor task during juxtacellular and multiunit recordings. Several distinct patterns of neuronal firing at an electrode site in relation to the forelimb-movement task were revealed during these multi-unit recordings.
Focus on results!
When research animals are stressed or distracted, training can slow and your results are what will suffer variability. Unlike other systems that allow rodents to essentially “run free” while attempting to perform tasks at the same time, Amuza’s TaskForcer eliminates those distractions—and their effects on your data.
*Isomura Y, Harukuni R, Takekawa T, Aizawa H, Fukai T. Microcircuitry coordination of cortical motor information in self-initiation of voluntary movements. Nat Neurosci. 2009 Dec;12(12):1586-93. doi: 10.1038/nn.2431. Epub 2009 Nov 8. PMID: 19898469.
Identifying efficient robust methods to monitor licking behavior in rodents is key to understanding the role of reward-oriented dopaminergic neural pathways in animal behavior. By monitoring licking behavior, researchers can better understand how rodents gauge the outcome of a specific reward, their incentive for the reward and how they predict the reward (1).
However, licking microcircuitries in the brain are complex, and incorporate a number of different neurons controlling different behaviors. A difficult task in recent times has been accurately identifying the specific microcircuit associated with each specific reward-oriented lick behavior.
The mesolimbic dopamine system is involved in reward-oriented behaviours, and dopamine antagonism in rodents has been shown to change ingestive behaviors. Pharmacology DAergic stimulation of the NAc triggers an intense response to obtain a reward, even if a rat has undergone extinction training (1). While ingestive behaviors include both feeding and drinking, the exact involvement in water drinking remains unclear.
As mice respond to sensory stimuli by licking for liquid rewards, precise monitoring of licking during these tasks provides an accessible metric of sensory-motor processing, particularly when combined with simultaneous neural recordings or microdialysis (2). The precise timing of reward consumption is critical to understand associations between neural activity and animal behavior. Therefore using the right detection method as well as a reliable rodent model of dopamine ensures that licks are monitored reliably (3).
Licking Units – Limitations to be considered
Some of the main challenges when developing and implementing lick detectors during head-restraint microdialysis or neurophysiological experiments in mice include:
Electrical contact sensors that trigger food or water feeder to dispense can create electrical artifacts that are similar to neural or behavioral amplitudes and time courses, which can also interfere with electrophysiology recordings (4).
Temporal characteristics of licking (approx 7Hz) are different from the profile of individual licks which are much faster. This is important if trying to determine the onset/offset of licks. If lick is being used to send TTL signals to other devices it can be troublesome.
Mice are small, so behavior can be disturbed by equipment that is bulky and obstructs animal view.
Head-restraining animals without proper habituation increases cortisol levels and could affect neural recordings / microdialysis. There it is important to ensure adequate training time
Contactless photo-sensors such as infrared detectors overcome these obstacles when monitoring lick behavior and remove any electrical artifact interference from the set-up.
Fig. 1: Transgenic construction of DSI mice.
Different promoters expressed in each line of transgenic model. Tamoxifen administration used to induce activation of transgenic phenotype. Dopaminergic synaptic vesicles are prevented from releasing neurotransmitters by v-SNARE cleaving in DSI models.
Case Study Drinking behavior was analyzed in triple transgenic mice generated with reduced DA release and treated with a D1-like or D2-like DA receptor agonist. Triple transgenic mice were generated to secrete reduced dopamine levels in the striatum and nucleus accumbent compared to control. These triple transgenic mice made fewer licks and fewer lick bursts than control under thirsty conditions. D1 or D2/3 receptor agonists were then administered to identify the influence of dopamine receptors in altered drinking behavior.
New triple transgenic mouse line expected to exhibit partial blockade of synaptic release rather than severely impaired DA secretion seen in other dopamine-depleted mice models. The DSI mouse line enables the study of phenotypes related to DA loss and the role of DAergic neurons and the DA receptors in drinking behavior.
Fig 2: Training of mice to lick for a water reward.
(a) Scheme of the training for licking test. (b) After 2 days of water deprivation, control and DSI mice were trained to lick a water nozzle for a water reward (4 μl/lick) (RM‐ANOVA:genotype, p < .05; time, p < .01). The daily water intake was limited to 1.5 ml per day, and the body weight was maintained at the same level (Ctrl, n = 16; DSI, n = 16). *p < .05 compared to Ctrl mice. Values are shown as the means ± SEMs
Experimental set-up The apparatus for licking training and data recording includes a water-pumping device and an infrared beam detector system which are controlled by software.
Thirsty mice showed vigorous activity when water was available, and they drank from different angles either in front of or under the water nozzle. This tendency reduced the accuracy of recording. Thus, the researchers utilized an apparatus (TaskForcer, O’Hara) that monitors neural circuits while a mouse is licking. A custom-made head plate was fixed onto a mouse’s skull with dental acrylic to reduce its head movements.
Assessed drinking behavior by analyzing licking microstructure
Number of licks and bursts
Size of bursts
Intraburst lick speed
A burst was defined as continuous licking (>2 licks with <0.4 s between licks).
After 2 days of water deprivation, the mouse was placed inside an acrylic tube and trained to lick for a water reward for 15 mins per day for 7 consecutive days.
Each interruption of the infrared beam counted as one lick, and the mouse was rewarded with one unit of water (4uL of water per lick).
Microdialysis was carried out using equipment supplied by Amuza Inc. to monitor levels of dopamine in the brain of both control and transgenic mice.
Fig 3: Scheme of the rat licking microstructure.
(a) The number of total licks carried out represents the extent of water drinking activity and therefore reflects the general drinking behavior. The number of bursts indicates the activation of responses and thus represents the incentive motivation triggered by reward cues. (b) DSI mice made fewer licks and bursts than the control littermates. The D1 receptor agonist ameliorated the lick number but did not increase the burst number, and the D2 receptor agonist suppressed all the measurement results from the licking test. The D1 agonist A68930 was effective only for DSI mice, but the D1 agonist SKF38393 was effective for both control and DSI mice
Results Findings suggest that D1 receptor activity impacts drinking and may also contribute to treatment for illnesses related to DA loss.
DSI mice avoid the infirmity and reduced food and water consumption exhibited by DA-deficient mice.
DSI mice showed impaired motor control when given a challenging rotarod test and made fewer licks and bursts than control mice.
One D1 receptor agonist increased the number of licks made by thirsty DSI mice. While another increased the number of licks made by DSI and control mice.
Combine Operant Tasks and Rewards
TaskForcer is the must-have modular system for in-vivo electrophysiology and imaging. Our operant-behavior conditioning system is designed around your priorities. The only animal training system that was created to speed training, simplify configuration, and deliver consistent results to expedite your discoveries.
(1) Kao K‐C, Hisatsune T.: Differential effects of dopamine D1‐like and D2‐like receptor agonists on water drinking behaviour under thirsty conditions in mice with reduced dopamine secretion. Eur J Neurosci. 2019;00:1–14. Ht References: (2) Williams, B., Speed, A., Haider, B: A novel device for real-time measurement and manipulation of licking behavior in head-fixed mice (2018) (3) Clark, Nicholas McKinley.: FAST, ACCURATE, AND LOW-COST SENSING OF REWARD CONSUMPTION AND LICK RESPONSES IN RODENTS (2018) (4) Hayar, A., Bryant, J.L., Boughter, J.D., Heck D.H.: A low-cost solution to measure mouse licking in an electrophysiological setup with a standard analog-to-digital converter (2008)