Sachs B D
Department of Psychology, University of Connecticut, Storrs 06269-1020, USA.
Neurosci Biobehav Rev. 1995 Summer;19(2):211-24. doi: 10.1016/0149-7634(94)00063-7.
Penile erections are usually classified as arising from "reflexogenic" or "psychogenic" causes. In practice this dichotomy has translated, somewhat circularly, to a distinction between spinal vs. supraspinal mediation, pelvic vs. hypogastric neural mediation, and perineal somesthetic stimulation vs. stimulation of receptors innervated by the cranial nerves. Evidence for differential regulation of erection in different contexts is reviewed. Research ascribing a physiological role to the hypogastric nerves in psychogenic erection, exemplified by classic studies of cats and spinally injured men, is suggestive but not compelling. Somewhat stronger is evidence that erection in some contexts (e.g., nocturnal penile tumescence (NPT) in humans or touch-stimulated erection in rats) is more sensitive to androgen levels than in other contexts (e.g., visual erotic stimuli in men or copulation in rats). However, some of these differences may arise from the relative erectogenic strength of the stimuli, rather than from qualitative differences in androgen sensitivity of different contexts. More compelling is the possibility that conflicting interpretations of the role of dopamine in erection may stem in large part from differences among laboratories in the context in which erection is evoked. In light of the evidence reviewed, it seems unlikely that the conventional reflexogenic-psychogenic dichotomy should be retained, at least in its present form. As a first step, it may be worth considering that reflexive erections may not be limited to somesthetic perineal stimulation, but rather may also include stimuli received via the cranial nerves. Two alternatives to the standard reflexogenic-psychogenic dichotomy are proposed. The first is a minor revision in which two senses of psychogenic erection are distinguished: the weak, commonly used, sense would include erection resulting from any extrinsic nonsomesthetic stimulation, whether visual, auditory, or chemosensory. In this sense, reflexive erections and psychogenic erections may not be mutually exclusive. The strong sense of psychogenic erection would be limited to memory and fantasy. The origins of psychogenic erection in both senses need not be available to consciousness, which may account for apparently spontaneous erections. In the second alternative taxonomy, erectogenic stimuli are classified as contact (somesthetic) or noncontact, and their action in evoking erection is placed on a continuum of reflexivity. Erectile contexts could then be considered as orthogonal to the other two dimensions. Even without a change in taxonomy, the conduct and interpretation of research into erectile function may be expected to benefit from closer attention to differences and similarities between contexts and species, and to context-sensitive differences in the regulation of erection.
阴茎勃起通常被归类为源于“反射性”或“心因性”原因。在实际应用中，这种二分法在某种程度上循环地转化为脊髓与脊髓以上介导、盆腔与腹下神经介导以及会阴躯体感觉刺激与由颅神经支配的受体刺激之间的区别。本文综述了不同情况下勃起差异调节的证据。将腹下神经在心因性勃起中的生理作用归因于研究，以对猫和脊髓损伤男性的经典研究为例，具有一定启发性但并不具有说服力。有证据表明，在某些情况下（例如人类的夜间阴茎勃起（NPT）或大鼠的触觉刺激勃起）勃起比在其他情况下（例如男性的视觉色情刺激或大鼠的交配）对雄激素水平更敏感，这一证据稍强一些。然而，其中一些差异可能源于刺激的相对勃起强度，而不是不同情况下雄激素敏感性的质的差异。更有说服力的是，多巴胺在勃起中的作用的相互矛盾的解释可能在很大程度上源于不同实验室诱发勃起的背景差异。鉴于所综述的证据，传统的反射性 - 心因性二分法似乎不太可能保留，至少以其目前的形式。作为第一步，可能值得考虑的是，反射性勃起可能不限于会阴躯体感觉刺激，还可能包括通过颅神经接收的刺激。本文提出了标准反射性 - 心因性二分法的两种替代方案。第一种是一个小的修订，其中区分了心因性勃起的两种含义：较弱的、常用的含义将包括由任何外在的非躯体感觉刺激引起的勃起，无论是视觉、听觉还是化学感觉。从这个意义上说，反射性勃起和心因性勃起可能并非相互排斥。心因性勃起的强烈含义将限于记忆和幻想。两种意义上心因性勃起的起源不一定为意识所察觉，这可能解释了明显的自发勃起。在第二种替代分类法中，勃起刺激被分类为接触性（躯体感觉）或非接触性，并且它们在诱发勃起中的作用被置于反射性的连续统一体上。然后可以将勃起情况视为与其他两个维度正交。即使分类法没有改变，对勃起功能的研究的进行和解释也可能受益于更密切地关注不同情况和物种之间的差异和相似性，以及勃起调节中对背景敏感的差异。
