Michael Levin Bioelectricity 101 Crash Course Lesson 36: Pavlovian Conditioning in Cells: Exploring Basal Cognition Summary
- Pavlovian conditioning (classical conditioning) is a fundamental form of learning where an association is formed between two stimuli: a neutral stimulus (NS) and an unconditioned stimulus (UCS) that naturally elicits a response.
- After repeated pairings of the NS and UCS, the NS becomes a conditioned stimulus (CS) and elicits the response even in the absence of the UCS. This is learning.
- This phenomenon is not limited to animals with nervous systems; it can occur in single cells, including bacteria, and in non-neural tissues. This represents a crucial example of basal cognition: forms of basic information process and responsiveness at the “bottom” layers (i.e. not waiting on multi-cellular coordination/structures) of biological hierarchy, far older in evolution and very wide-spread (cells)
- Cellular mechanisms for Pavlovian conditioning can involve changes in:
- Ion channel activity and membrane potential.
- Gene expression and protein synthesis.
- Cytoskeletal organization.
- Bioelectric network dynamics.
- Computational models, such as Boolean networks, can be used to simulate and understand associative learning in cellular pathways.
- The existence of Pavlovian conditioning in cells suggests that:
- Cells can store and retrieve information about past experiences.
- Cellular responses can be context-dependent (influenced by prior stimuli).
- Biomedical interventions can potentially train cells and tissues to respond in desired ways.
- A definition of cognition, beyond nerves/brains is very beneficial, that works at this cellular-level understanding.
Michael Levin Bioelectricity 101 Crash Course Lesson 36: Pavlovian Conditioning in Cells: Exploring Basal Cognition
Up to this point, we’ve focused primarily on the mechanisms of bioelectricity – how cells generate and respond to electrical signals, and how these signals influence development, regeneration, and other processes. We’ve seen that cells are not simply passive recipients of instructions from genes; they actively participate in shaping their own behavior and the behavior of their neighbors. Now, we’re going to take a conceptual leap and explore an even more surprising aspect of cellular behavior: the capacity for learning. Specifically, we’ll focus on a fundamental form of learning called Pavlovian conditioning, and its implications for understanding “basal cognition” – the cognitive-like abilities of cells and tissues.
Most people are familiar with Pavlov’s famous experiments with dogs. In these experiments, Pavlov repeatedly paired a neutral stimulus (NS) – like the sound of a bell – with an unconditioned stimulus (UCS) – like the presentation of food – that naturally elicited a response (salivation). After repeated pairings, the dogs learned to associate the bell with the food. The bell, which initially had no effect on salivation, became a conditioned stimulus (CS) that could elicit salivation even in the absence of food. This is Pavlovian conditioning, also known as classical conditioning.
The key idea is that the organism learns a predictive relationship between two events: the CS predicts the occurrence of the UCS. This allows the organism to anticipate and prepare for the UCS, even before it actually arrives. This is a powerful form of learning because it allows organisms to adapt to their environment and respond effectively to changing conditions.
Now, you might be thinking: “That’s interesting, but what does it have to do with cells? Dogs have brains and nervous systems; cells don’t.” That’s where the concept of basal cognition comes in. Basal cognition refers to the basic information-processing and decision-making abilities of cells and tissues, even in the absence of a nervous system. It’s the idea that all living systems, from bacteria to plants to animals, exhibit some degree of “intelligence” – the ability to sense their environment, process information, and make adaptive responses. Pavlovian conditioning, it turns out, is a fundamental example of basal cognition. It can occur in single cells, and in non-neural tissues, without any need for a brain or nervous system.
How is this possible? How can a single cell learn to associate two stimuli? The answer lies in the complex molecular machinery within the cell, including:
- Ion Channels and Membrane Potential: As we’ve discussed extensively, ion channels control the flow of ions across the cell membrane, creating the membrane potential. Changes in membrane potential can act as signals, influencing other cellular processes.
- Mechanism: The UCS might cause a large change in membrane potential (e.g., a depolarization). The NS might cause a smaller change. If these changes occur together repeatedly, the cellular machinery might “learn” to associate the small change (NS) with the large change (UCS). This could happen, for example, through changes in the sensitivity of ion channels, or through changes in the expression of genes that encode ion channels.
- Gene Expression and Protein Synthesis: The activation of signaling pathways by stimuli can lead to changes in gene expression – turning genes “on” or “off” – and therefore changes in the production of specific proteins.
- Mechanism: The UCS might activate a signaling pathway that leads to the production of a protein that causes a specific response (e.g., cell division, migration, etc.). The NS might activate a different pathway. If these pathways are repeatedly activated together, the cell might “learn” to activate the response pathway even when only the NS is present. This could involve changes in the expression of transcription factors, or modifications to chromatin (the structure that packages DNA) that make certain genes more or less accessible.
- Cytoskeletal Organization: The cytoskeleton, as we discussed in Lesson 24, is a dynamic network of protein filaments that controls cell shape, movement, and internal organization. Changes in the cytoskeleton can be triggered by external stimuli.
- Mechanism: The UCS might cause a change in the cytoskeleton that leads to a specific cellular response (e.g., cell migration). The NS might cause a smaller change. Repeated pairing could lead to the cytoskeleton “remembering” the association, so that even the NS alone can trigger the response. This could involve changes in the polymerization of actin or microtubules, or changes in the activity of motor proteins.
- Bioelectric Networks: As we’ve seen in previous lessons, cells can communicate with each other through bioelectric signals, mediated by ion channels and gap junctions. These networks can exhibit complex dynamics, including stable patterns of voltage that can act as a form of “memory.”
- Mechanism: The UCS might cause a change in the bioelectric pattern across a group of cells. The NS might cause a smaller change. Repeated pairing could “train” the network to associate the smaller change (NS) with the larger change (UCS), leading to a stable alteration in the network’s bioelectric state. This could be analogous to how memories are stored in the brain through changes in the strength of connections between neurons (synaptic plasticity).
These are just some of the possible cellular mechanisms for Pavlovian conditioning. The key point is that cells are not passive devices; they are dynamic, information-processing systems capable of learning and adapting to their environment.
The paper by Biswas et al. (2021), which we summarized earlier, provides strong computational evidence for Pavlovian conditioning (associative memory) in gene regulatory networks (GRNs). They showed that Boolean network models of GRNs can “learn” to associate a neutral stimulus (activation of a specific gene) with an unconditioned stimulus (activation of another gene), such that the neutral stimulus becomes a conditioned stimulus that can trigger the response. This learning occurs without any changes in the network’s wiring (the connections between genes); it’s a purely dynamical phenomenon, arising from the way the network processes information over time.
What are the implications of Pavlovian conditioning in cells for biomedicine and our understanding of life?
- Drug Resistance and Tolerance: As discussed in the previous lesson, drug tolerance and sensitization can be understood as forms of cellular learning. Understanding the mechanisms of Pavlovian conditioning in cells could lead to new strategies for preventing or overcoming drug resistance.
- Placebo and Nocebo Effects: The placebo effect (where a sham treatment has a beneficial effect) and the nocebo effect (where a sham treatment has a harmful effect) are likely mediated, at least in part, by Pavlovian conditioning. The context of treatment (e.g., the doctor’s words, the environment of the clinic) can become associated with the effects of a drug, leading to a conditioned response even in the absence of the active drug. Understanding this could lead to ways to enhance the placebo effect and minimize the nocebo effect.
- Regenerative Medicine: Bioelectric signals are crucial for regeneration, and these signals can be influenced by past experiences. It might be possible to “train” tissues to regenerate by applying specific patterns of bioelectric stimulation, effectively conditioning them to activate regenerative pathways.
- Cancer Therapy: Cancer cells exhibit abnormal bioelectric patterns and can “learn” to evade chemotherapy. Understanding how cancer cells adapt to their environment could lead to new strategies for overcoming drug resistance and reprogramming cancer cells to a normal state.
- Understanding Development: Embryonic development involves complex sequences of signals and responses. Pavlovian conditioning could play a role in how cells “learn” their fate and position within the developing embryo.
- Rethinking Disease and Treatment: The existence of Pavlovian conditioning in cells suggests that we need to move beyond a purely mechanistic view of disease and treatment. We need to consider the context, the history, and the learning capacity of cells and tissues.
In summary, Pavlovian conditioning in cells is a powerful example of basal cognition – the ability of cells to learn, remember, and adapt to their environment. This opens up exciting new avenues for research and for developing novel biomedical interventions that exploit the inherent intelligence of living systems. This involves new types of learning and memory that genes can implement directly, that go far beyond waiting on DNA to replicate.
Michael Levin Bioelectricity 101 Crash Course Lesson 36: Pavlovian Conditioning in Cells: Exploring Basal Cognition Quiz
1. What is Pavlovian conditioning (classical conditioning)?
A) A type of operant conditioning where behavior is modified by rewards and punishments.
B) A form of learning where an association is formed between a neutral stimulus and an unconditioned stimulus.
C) A type of gene therapy that alters DNA sequences.
D) A surgical procedure to remove damaged tissue.
2. What is the unconditioned stimulus (UCS) in Pavlov’s original experiments?
A) The sound of a bell
B) The sight of food
C) The salivation of the dog
D) The training of the dog
3. What is the conditioned stimulus (CS) in Pavlov’s experiments *after* conditioning?
A) The sound of a bell
B) The sight of food
C) The salivation of the dog
D) The experimenter
4. True or False: Pavlovian conditioning can only occur in animals with nervous systems.
A) True
B) False
5. What is basal cognition?
A) The cognitive abilities of highly intelligent animals
B) Basic learning/information-proccessing found within individual cells and tissues.
C) A form of artifical intelligence.
D) All of the above.
6. Which of the following cellular mechanisms could potentially be involved in Pavlovian conditioning?
A) Changes in ion channel activity
B) Changes in gene expression
C) Changes in cytoskeletal organization
D) All of the above
7. What type of computational model did Biswas et al. (2021) use to study associative learning in cellular pathways?
A) Artificial neural networks
B) Boolean networks
C) Agent-based models
D) Differential equations
8. What did Biswaas’s paper study and demonstrate with a computational model?
A) Basic forms of associative memory and other learning
B) Genetic changes leading to cancer resistance
C) Drug affects over time
D) Only A and C
9. True or False: The existence of Pavlovian conditioning in cells suggests that cellular responses are always predictable and determined solely by their current environment.
A) True
B) False
10. How might understanding Pavlovian conditioning in cells be relevant to medicine?
A) It could help explain drug tolerance and resistance.
B) It could suggest new strategies for regenerative medicine.
C) It could provide insights into the placebo effect.
D) All of the above
11. What is a key feature of “learning”, in a generalized sense, that is not specific to humans or animals only?
A) Change of behaviour from events over a period of time.
B) Memory that changes response to same stimulous after “learning”.
C) Associative learning of previously-unconnected elements, as conditioning does.
D) All of the above.
12. The bioelectric “software” in this metaphor indicates…:
A) Electrical changes across a network and bioelectric gradients that represent memory/state of cells, alongside ability to read/interpret that information.
B) DNA acting alone.
C) Specific mRNA regulation, alone.
D) Genetic expressions.
13. A “top down” control means
A) Genetic control alone.
B) Molecular-focused solutions to tissues.
C) A form of control leveraging higher-level behaviors to influence cellular-level processes.
D) An entirely bottom-up type of emergent behavior that requires very tight micromanagement.
14. The concept of “Memory” when used here indicates, generally..
A) Only in the traditional form in human or animal minds.
B) Only in single cells
C) Can involve any network/organ system.
D) None of the Above
15. True/False: Learning as the change/update of dynamical networks applies beyond cellular pathways.
A) True
B) False
16. “Conditioned tolerance” can mean…:
A) Overdose may occur with normal dosage if someone changes a previously strongly-held routine associated with dosage
B) Increased intake of alcohol may increase tolerance over time.
C) Nothing; conditioning, as from associative learning (pairing stimulus/response), does not impact phsyiological systems outside brain areas.
D) All of the Above.
17. What’s a major theme here?:
A) The need to be extremely reductionist and ignore wider biological and system processes for biomedical insight
B) Biology/genetics are so specific that learnings from fields as Neuroscience offer no important or deep relationship to other levels/kinds of life and networks.
C) Behaviour-shaping as an overall medical approach.
D) Ignoring concepts in evolution for greater accuracy of understanding.
18. Examples of basal congition involves which phenomena/concept…?
A) Homeostasis
B) Robustness.
C) Navigation of external or internal space
D) All of the above
19. Why aren’t GRNs equivalent to computers in traditional understandings?
A) GRNs can’t change without physical or gene re-arrangements (the ‘wiring”), like earlier machines.
B) A key learning component to GRNs and how inputs over time affects their state, are still ignored.
C) Memory isn’t taken into consideration.
D) All of the above
20. The experiments done here include a major conceptual point that links..
A) Cognition with cell dynamics
B) Biology/learning with “computation”.
C) Top-down and context-specific learning alongside other biochemical and pathway factors
D) All of the above.
Michael Levin Bioelectricity 101 Crash Course Lesson 36: Pavlovian Conditioning in Cells: Exploring Basal Cognition Answer Sheet
1. B
2. B
3. A
4. B
5. B
6. D
7. B
8. D
9. B
10. D
11. D
12. A
13. C
14. C
15. A
16. A
17. C
18. D
19. D
20. D
迈克尔·莱文 生物电 101 速成课程 第36课：细胞中的巴甫洛夫条件反射：探索基础认知 摘要
- 巴甫洛夫条件反射（经典条件反射）是一种基本的学习形式，其中在中性刺激 (NS) 和自然引起反应的非条件刺激 (UCS) 之间建立关联。
- 在 NS 和 UCS 重复配对后，NS 成为条件刺激 (CS)，即使在没有 UCS 的情况下也能引起反应。这就是学习。
- 这种现象不仅限于有神经系统的动物；它可以发生在单细胞中，包括细菌，以及非神经组织中。这代表了基础认知的一个关键例子：生物等级中“底层”（即不依赖多细胞协调/结构）的基本信息处理和反应形式，在进化上更古老，分布非常广泛（细胞）。
- 巴甫洛夫条件反射的细胞机制可能涉及以下变化：
- 离子通道活性和膜电位。
- 基因表达和蛋白质合成。
- 细胞骨架组织。
- 生物电网络动力学。
- 计算模型，例如布尔网络，可用于模拟和理解细胞通路中的联想学习。
- 细胞中存在巴甫洛夫条件反射表明：
- 细胞可以存储和检索有关过去经历的信息。
- 细胞反应可以是情境依赖性的（受先前刺激的影响）。
- 生物医学干预有可能训练细胞和组织以所需的方式做出反应。
- 超越神经/大脑的认知定义非常有益，可以在这个细胞水平的理解上发挥作用。
迈克尔·莱文 生物电 101 速成课程 第36课：细胞中的巴甫洛夫条件反射：探索基础认知
到目前为止，在本课程中，我们主要关注生物电的机制——细胞如何产生和响应电信号，以及这些信号如何影响发育、再生和其他过程。我们已经看到，细胞不仅仅是被动地接受来自基因的指令；它们积极参与塑造自身的行为和邻近细胞的行为。现在，我们将进行一个概念上的飞跃，探索细胞行为的一个更令人惊讶的方面：学习能力。具体来说，我们将关注一种基本的学习形式，称为巴甫洛夫条件反射，以及它对理解“基础认知”——细胞和组织的类认知能力——的意义。
大多数人都熟悉巴甫洛夫著名的狗实验。在这些实验中，巴甫洛夫反复将中性刺激 (NS)——例如铃声——与非条件刺激 (UCS)——例如呈现食物——配对，后者会自然地引起反应（流涎）。经过反复配对，狗学会了将铃声与食物联系起来。铃声最初对流涎没有影响，但后来变成了条件刺激 (CS)，即使在没有食物的情况下也能引起流涎。这就是巴甫洛夫条件反射，也称为经典条件反射。
关键在于，生物体学习了两个事件之间的预测关系：CS 预测 UCS 的发生。这使得生物体能够预期并准备迎接 UCS，甚至在它真正到来之前。这是一种强大的学习形式，因为它允许生物体适应其环境并对不断变化的条件做出有效反应。
现在，您可能会想：“这很有趣，但这与细胞有什么关系呢？狗有大脑和神经系统；细胞没有。” 这就是基础认知的概念发挥作用的地方。基础认知是指细胞和组织的基本信息处理和决策能力，即使在没有神经系统的情况下也是如此。这个观点认为，所有生命系统，从细菌到植物再到动物，都表现出某种程度的“智能”——感知环境、处理信息和做出适应性反应的能力。事实证明，巴甫洛夫条件反射是基础认知的一个基本例子。它可以发生在单细胞中，也可以发生在非神经组织中，不需要任何大脑或神经系统。
这怎么可能呢？单个细胞如何学会将两个刺激联系起来？答案在于细胞内复杂的分子机制，包括：
- 离子通道和膜电位：正如我们已经广泛讨论过的，离子通道控制离子跨细胞膜的流动，从而产生膜电位。膜电位的变化可以作为信号，影响其他细胞过程。
- 机制： UCS 可能会导致膜电位发生较大变化（例如，去极化）。NS 可能会导致较小的变化。如果这些变化反复同时发生，细胞机制可能会“学会”将较小的变化 (NS) 与较大的变化 (UCS) 联系起来。例如，这可能通过离子通道敏感性的变化或编码离子通道的基因表达的变化来实现。
- 基因表达和蛋白质合成： 刺激激活信号通路可以导致基因表达的变化——打开或关闭基因——从而导致特定蛋白质的产生发生变化。
- 机制： UCS 可能会激活导致产生某种蛋白质的信号通路，该蛋白质会引起特定的反应（例如，细胞分裂、迁移等）。NS 可能会激活不同的通路。如果这些通路反复一起被激活，细胞可能会“学会”即使只有 NS 存在时也会激活反应通路。这可能涉及转录因子表达的变化，或染色质（包装 DNA 的结构）的修饰，使某些基因更容易或更难接近。
- 细胞骨架组织： 正如我们在第 24 课中讨论的，细胞骨架是一个动态的蛋白质丝网络，控制着细胞的形状、运动和内部组织。细胞骨架的变化可以由外部刺激触发。
- 机制： UCS 可能会导致细胞骨架发生变化，从而导致特定的细胞反应（例如，细胞迁移）。NS 可能会导致较小的变化。反复配对可能会导致细胞骨架“记住”这种关联，从而使单独的 NS 也能触发反应。这可能涉及肌动蛋白或微管聚合的变化，或运动蛋白活性的变化。
- 生物电网络： 正如我们在前面的课程中所看到的，细胞可以通过生物电信号相互通信，这些信号由离子通道和间隙连接介导。这些网络可以表现出复杂的动力学，包括可以作为一种“记忆”形式的稳定电压模式。
- 机制: UCS可能会导致细胞群生物电模式的改变. NS可能会引起较小的变化。 重复配对可以“训练”网络, 使较小的变化 (NS) 与较大的变化 (UCS) 相关联，导致网络生物电状态的稳定改变。 这可能类似于记忆如何通过神经元之间连接强度的变化（突触可塑性）存储在大脑中.
这些只是巴甫洛夫条件反射的一些可能的细胞机制。关键在于细胞不是被动装置；它们是能够学习和适应环境的动态信息处理系统。
我们之前总结过的 Biswas 等人 (2021) 的论文为基因调控网络 (GRN) 中的巴甫洛夫条件反射（联想记忆）提供了强有力的计算证据。他们表明，GRN 的布尔网络模型可以“学习”将中性刺激（特定基因的激活）与非条件刺激（另一个基因的激活）联系起来，从而使中性刺激成为可以触发反应的条件刺激。这种学习无需任何网络布线（基因之间的连接）的变化；这是一种纯粹的动力学现象，源于网络随时间处理信息的方式。
细胞中的巴甫洛夫条件反射对生物医学和我们对生命的理解有什么意义？
- 耐药性和耐受性： 正如我们在上一课中讨论的那样，药物耐受性和敏化可以理解为细胞学习的形式。了解细胞中巴甫洛夫条件反射的机制可能会导致预防或克服耐药性的新策略。
- 安慰剂和反安慰剂效应： 安慰剂效应（假治疗具有有益效果）和反安慰剂效应（假治疗具有有害效果）可能至少部分由巴甫洛夫条件反射介导。治疗的背景（例如，医生的言语、诊所的环境）可以与药物的效果相关联，即使在没有活性药物的情况下也会导致条件反应。了解这一点可以带来增强安慰剂效应和最小化反安慰剂效应的方法。
- 再生医学： 生物电信号对再生至关重要，并且这些信号会受到过去经验的影响。通过应用特定的生物电刺激模式，有可能“训练”组织再生，有效地将它们调节为激活再生途径。
- 癌症治疗： 癌细胞表现出异常的生物电模式，并且可以“学会”逃避化疗。了解癌细胞如何适应其环境可以带来克服耐药性和将癌细胞重新编程为正常状态的新策略。
- 了解发育： 胚胎发育涉及复杂的信号和反应序列。巴甫洛夫条件反射可能在细胞“学习”其在发育中胚胎内的命运和位置方面发挥作用。
- 重新思考疾病和治疗：细胞中存在巴甫洛夫条件反射表明我们需要超越纯粹的机械疾病和治疗观点。我们需要考虑细胞和组织的背景、历史和学习能力。
总之，细胞中的巴甫洛夫条件反射是基础认知的一个强有力例子——细胞学习、记忆和适应环境的能力。这为研究开辟了令人兴奋的新途径，并为开发利用生命系统固有智能的新型生物医学干预措施提供了可能。这涉及新的学习和记忆类型，基因可以直接实现这些类型，远远超出了等待 DNA 复制。
迈克尔·莱文 生物电 101 速成课程 第36课：细胞中的巴甫洛夫条件反射：探索基础认知 小测验
1. 巴甫洛夫条件反射（经典条件反射）是什么？
A) 一种操作性条件反射，其中行为通过奖励和惩罚来改变。
B) 一种学习形式，其中在中性刺激和非条件刺激之间建立关联。
C) 一种改变 DNA 序列的基因治疗。
D) 一种切除受损组织的手术。
2. 巴甫洛夫最初实验中的非条件刺激 (UCS)是什么？
A) 铃声
B) 食物的景象
C) 狗的流涎
D) 狗的训练
3. 巴甫洛夫实验中条件刺激 (CS)在条件反射之后是什么？
A) 铃声
B) 食物的景象
C) 狗的流涎
D) 实验者
4. 对或错：巴甫洛夫条件反射只能发生在有神经系统的动物中。
A) 对
B) 错
5. 什么是基础认知？
A) 高度智能动物的认知能力
B) 存在于个体细胞和组织内的基本学习/信息处理。
C) 一种人工智能形式。
D) 以上都是。
6. 以下哪种细胞机制可能参与巴甫洛夫条件反射？
A) 离子通道活性的变化
B) 基因表达的变化
C) 细胞骨架组织的变化
D) 以上都是
7. Biswas 等人 (2021) 使用什么类型的计算模型来研究细胞通路中的联想学习？
A) 人工神经网络
B) 布尔网络
C) 基于主体的模型
D) 微分方程
8. Biswaas 的论文研究并用计算模型证明了什么？
A) 联想记忆和其他学习的基本形式
B) 导致癌症耐药性的基因变化
C) 药物随时间推移的影响
D) 仅 A 和 C
9. 对或错：细胞中存在巴甫洛夫条件反射表明细胞反应总是可预测的，并且仅由其当前环境决定。
A) 正确
B) 错误
10. 了解细胞中的巴甫洛夫条件反射与医学有什么关系？
A) 它可以帮助解释药物耐受性和耐药性。
B) 它可以为再生医学提供新的策略。
C) 它可以提供对安慰剂效应的见解。
D) 以上都是
11. 广义上讲，“学习”的一个关键特征是什么，它不仅仅是人类或动物所特有的？
A) 行为因一段时间内的事件而发生变化。
B) 改变对“学习”后相同刺激的反应的记忆。
C) 以前不相关的元素的联想学习，如条件反射。
D) 以上都是.
12. 在这个比喻中，生物电“软件”表示…：
A) 跨网络的电变化和代表细胞记忆/状态的生物电梯度，以及读取/解释该信息的能力。
B) 单独的DNA。
C) 单独的特定 mRNA 调控。
D) 基因表达。
13. “自上而下”的控制意味着
A) 单独的遗传控制。
B) 以分子为中心的组织解决方案。
C) 一种利用更高级行为来影响细胞水平过程的控制形式。
D) 一种完全自下而上的涌现行为，需要非常严格的微观管理。
14. 这里使用的“记忆”概念通常表示..
A) 仅在人或动物大脑中的传统形式.
B) 仅在单细胞中
C) 可以涉及任何网络/器官系统.
D) 以上都不是
15. 对或错：作为动态网络的变化/更新的学习适用于细胞通路之外。
A) 对
B) 错
16. “条件耐受”可能意味着…：
A) 如果有人改变了以前与剂量相关的强烈保持的惯例，则正常剂量可能会导致过量
B) 随着时间的推移，酒精摄入量的增加可能会增加耐受性。
C) 没有；条件反射，如联想学习（配对刺激/反应），不会影响大脑区域以外的生理系统。
D) 以上都是.
17. 这里的一个主要主题是什么？：
A) 需要极度还原论并忽略更广泛的生物学和系统过程以获得生物医学见解
B) 生物学/遗传学非常具体，以至于神经科学等领域的学习与其他生命水平/类型和网络没有重要或深刻的关系。
C) 作为整体医疗方法的行为塑造.
D) 忽略进化概念以获得更准确的理解.
18. 基础认知的例子包括哪些现象/概念…？
A) 稳态
B) 稳健性.
C) 外部或内部空间的导航
D) 以上都是
19. 为什么传统的理解中 GRN 不等同于计算机？
A) GRN 不能在没有物理或基因重新排列（“布线”）的情况下进行更改，就像早期的机器一样。
B) GRN 的关键学习组成部分以及输入随时间推移如何影响其状态，仍然被忽视。
C) 记忆没有被考虑在内.
D) 以上都是
20. 这里完成的实验包括一个主要的 概念要点, 将其联系起来..
A) 认知与细胞动力学
B) 生物学/学习与“计算”。
C) 自上而下和特定于上下文的学习以及其他生化和通路因素
D) 以上都是.
迈克尔·莱文 生物电 101 速成课程 第36课：细胞中的巴甫洛夫条件反射：探索基础认知 答案表
1. B
2. B
3. A
4. B
5. B
6. D
7. B
8. D
9. B
10. D
11. D
12. A
13. C
14. C
15. A
16. A
17. C
18. D
19. D
20. D